This article analyses the legal origins of the ‘substance of rights’ doctrine, and its judicial development since its creation in landmark Union citizenship cases over a decade ago. It is demonstrated how the status of Union citizenship has evolved from being a proclaimed fundamental status for the individual in a lawful cross-border situation, to an increasingly operational and legally effective status regardless of the nature of the free movement situation. Under a genuinely substantive status of Union citizenship, any and all Member States are obligated to neither restrict freedom of movement under art. 21 TFEU, nor deprive, de jure or de facto, a Union citizen of the genuine enjoyment of the substance of Union citizenship rights under art. 20 TFEU. Thereby, the relevance of art. 20 TFEU is no longer reserved to the Union citizen’s relationship to their home Member State. In addition, it is argued that, as the jurisdictional spheres of art. 21 TFEU and 20 TFEU merge, the legal mechanisms of EU fundamental rights protection should also be streamlined across Directive 2004/38, art. 21 TFEU and art. 20 TFEU; thereby giving further substance to the citizenship ideal of civis europaeus sum.
1 Introduction: The Substantiated Status of Union Citizenship
The status of Union citizenship has had almost 30 years of legal life in EU law. In review, it has had a tangible impact on the law of the internal market, personal free movement rights, as well as the development of EU fundamental rights standards.1 Its legal development has however not been smooth sailing. Notably, the fluctuations in the jurisprudence of the Court of Justice (the Court) between ‘rights enhancing’ and ‘state deferring’ interpretations of equal treatment rights of Union citizens in a free movement situation have been the subject of much scrutiny and critique.2
Intertwined with the issue of non-discrimination on grounds of nationality is the complex body of case law on family reunification rights for Union citizens and their family members. The legal evolution in this area has been criticised for resulting in reverse discrimination between moving and static Union citizens.3 Such family residence rights are variably attainable under either secondary legislation, or directly under art. 21 TFEU, and, as developed in the most recent decade, directly under art. 20 TFEU. The latter provision is the legal basis for the particular strand of jurisprudence on Union citizenship, which triggers the application of Union law also without free movement law’s necessary cross-border element. The relevant legal issue for triggering art. 20 TFEU concerns a threat to the effectiveness of the status of Union citizenship itself,4 which generates an obligation on the Member States of ‘non-deprivation’ of the genuine enjoyment of the ‘substance of rights’ of Union citizenship.5
The substance of rights doctrine has, throughout its legal development in the 2010’s, demonstrated a spectrum of judicial innovation, minimalism, and more recently, expansion.6 Starting with the formula famously seen in the Ruiz Zambrano judgment:
“… art. 20 TFEU precludes national measures which have the effect of depriving citizens of the Union of the genuine enjoyment of the substance of the rights conferred by virtue of their status as citizens of the Union …”7
With those words, the substance of rights doctrine established nothing less than a new jurisdictional frontier of Union law into the Member States’ sphere of competences, which has since triggered a vast scholarly output.8 The rationale for making Union citizenship applicable to legal spaces where free movement law would normally not apply, had already been expressed in the Opinion of Advocate General (AG) Poiares Maduro in the prior Rottmann case. He argued that not only issues concerning the exercise of Union citizenship rights and duties are within the scope of Union law. There must also be some effect on the Member States’ competence within the sphere of the status of Union citizenship itself.9
In the case law of the last decade, the idea that the legal and practical existence of an individual’s Union citizenship is intertwined with and is as relevant to protect as the individual’s exercise of the rights that ensue from that status, has matured. It should however not be assumed that art. 20 TFEU may only take effect in instances of no connection to freedom of movement, and would therefore be relevant only in the Union citizen’s relationship to his or her home Member State.10,11 The case law shows an increasing streamlining of how to review Member State interferences with either art. 21 or 20 TFEU. While the latter has had the character of being the supplementary ‘last resort’ to art. 21 TFEU, recent developments show might also take effect in the Union citizen’s relationship to his or her host Member State when in a free movement situation.12 The more the respective jurisdictional scope of art. 20 and 21 TFEU merge, the less relevant will it be to distinguish between situations with or without a cross-border element. It is argued in this article that such a distinction is not purposeful within the substance of rights doctrine, and should explicitly be done away with, in order to streamline the availability of EU fundamental rights protection for Union citizens whether it be under secondary law such as Directive 2004/38,13 or primary law, such as art. 21 TFEU, or art. 20 TFEU.14 This way, Union citizenship may truly function as an operational status of genuine substance, following its proclaimed destiny.
The purpose of this article is to explore the legal origins and development of the jurisprudence of the substance of rights doctrine and its effect of operationalising the status of Union citizenship, regardless of freedom of movement. First, the article traces the doctrine’s roots back to the early Union citizenship cases of the 1990s.15
Second, it analyses the last decade of judicial development, starting with the Rottmann, and Ruiz Zambrano judgments, which effectively launched the doctrine as a legal tool in the Court’s judicial box.16 These two cases were immediately followed by the Court’s retraction of the legal scope and applicability of the substance of rights doctrine, reigning in the reach of the fundamental status of Union citizenship under art. 20 TFEU (2012–2015).17 As from 2016 however, art. 20 TFEU has resurged as a legally potent basis for protecting Union citizenship, generating residence and equal treatment rights for the third country national (TCN) family members that applicant Union citizens depend on.
Third, the article discusses how fundamental rights review under the Charter (CFR)18 is activated for assessing both an interference in the shape of a restriction on freedom of movement under art. 21 TFEU, and an interference in the shape of deprivation under art. 20 TFEU, but tends to echo absently in cases solved within the Directive 2004/38.
Finally, it is argued that the operationalisation of Union citizenship for the activation of fundamental rights protection under Union law could remedy such discrepancies.
In conclusion, the intended fundamental status of Union citizenship has not yet reached its destiny’s fulfilment, neither through freedom of movement, nor the substance of rights doctrine, rather, it continues its process of unfolding.
2 The Trajectory of the Substance of Rights Doctrine (1995–Present)
2.1 The Fundamental Status of Union Citizenship: Proclaiming a Destiny (1995–2009)
Early citizenship cases such as Sala, Grzelczyk, and Baumbast all had clear cross-border dimensions to them, which placed them within free movement law. In turn, the proclaimed ‘fundamental status of Union citizenship’ provided the jurisdictional parameter for expanding the scope and interpretation of the rights of residence, equal treatment, and family reunification. The Court was implicitly, perhaps even unknowingly, paving the ground for allowing art. 20 TFEU to one day spring forth as a legally forceful centrepiece.
The status of Union citizenship granted to every national of the Member States, established in primary law through the 1993 Treaty of Maastricht and presently found in art. 20 TFEU (ex art. 17 TEC), dwelled at the side-lines of the Court’s first judgments after its introduction in the free movement of persons cases issued around the turn of the millennium.19 While the predecessor to art. 20 TFEU was not the direct legal issue in the well-known equal treatment case of Grzelczyk, the force of this provision was an essential element to the Court’s famous proposition made there: “Union citizenship is destined to be the fundamental status of nationals of the Member States”.20 In that statement, lies the first substantiation of the status of Union citizenship itself, enabling the right to equal treatment to function as a right tied directly to the individual who is in a lawful free movement situation, rather than functioning only to facilitate the exercise of freedom of movement.21
While often repeating this statement, the early citizenship cases nevertheless exclusively concerned interpretations of free movement rights for Union citizens and their family members in a cross-border situation, thereby triggering the scope of art. 21 TFEU (ex art. 18 TEC) and, usually, the relevant Residence Directives.22 The self-standing importance of the status of Union citizenship only implicitly served to abridge the jurisdictional gap between the individual outside of the economic status of the worker or self-employed person, to the rights of residence and equal treatment stemming directly from the Treaty’s free movement of persons provisions.23 As the Court found in Grzelczyk; citizenship of the Union did not automatically amount to a right to equal treatment in every instance, but it could serve to determine the jurisdictional sphere of application of the prohibition on discrimination on grounds of nationality of art. 18 TFEU (ex art. 12 TEC).24
In his Opinion in the Sala case, AG La Pergola forcibly launched the idea of Union citizenship as the fundamental status of the person, which only the loss of Member State nationality could subtract from.25 While the issues in Sala was that of equal treatment when exercising freedom of movement to a host Member State, there was already an awareness that to lose the status of Union citizenship, would be to lose something legally substantial.26 The AG argued that an individual holding Union citizenship, who is legally present in a host member State, must come within the rationae personae of the EU legal principle of non-discrimination on grounds of nationality.27 The various legislated conditions to the exercise of a right of residence in free movement law, could not subtract from the existence of such an essential right.28 From this viewpoint, the personal status of Union citizenship had the potential to develop its own legal forcefulness, separated from the actual exercise of freedom of movement.
The material relevance of the status of Union citizenship itself was formulated in the subsequent Grzelczyk and Trojani judgments, and bridged the gap between the rights of the job seeker to those of a worker in the Collins case.29 Union citizenship increasingly appeared as a conceptually overarching umbrella to connect the cross-border worker, service recipient and provider, the student, and the accompanying family members to one fundamental status.30
The fundamental status of Union citizenship served as the argumentative basis for establishing the right to equal treatment as a substantial Union citizenship right in Sala, Grzelczyk and Trojani. Thereby, what is now art. 18 TFEU expressed a right linked directly to the individual Union citizen, regardless of what sort of freedom of movement that was being pursued in a given case.31 In D’Hoop, the Court referred to equality of treatment when in a free movement situation as one of “the principles which underpin the status of citizen of the Union”.32 The right of residence, as part of non-economically motivated use of freedom of movement in art. 21 TFEU, took a similar trajectory in the Baumbast case, and was pronounced to be a directly effective Union citizenship right.33
In the 2001 Opinion of AG Geelhoed in Baumbast, he referred to the right to free movement as “the essence” of Union citizenship,34 and argued for the right to move and reside freely in art. 21 TFEU as a directly effective right, in a moment in time where this provision’s scope of application and legal effects, were still unclear.35 To give direct effect to residence under art. 21 TFEU would be to recognise it as a right of “substance”,36 meaning that any limits and conditions to its exercise must not rob it of its substantive content.37
Not only did the judgment that followed in Baumbast rely on the fundamental status of Union citizenship for declaring the direct effect of art. 21 TFEU; it also used Union citizenship to bridge a legal gap in the protection of family members of cross-border workers.38 The effect was that the children of a former cross-border worker were instead regarded as children of a Union citizen – giving them a standing under Union law also if the parent had ceased being an economically active person. In addition, the legal standing of the children was fortified by the fact that they might themselves be Union citizens, meaning that they had a fundamental status to reckon with under Union law, independent of their parents, and legally relevant also for minors.39
To ensure the child’s effective enjoyment of its rights, the child must also be guaranteed a right to be accompanied in the host Member State by its primary carer irrespective of that carer’s nationality or economic resources.40 This was explicitly tied to both the effet utile of the child’s right to education and right to reside, as well as to the fundamental right to respect to family life as found in art. 8 of the ECHR.41 To not grant the primary carer a right to reside together with the child would deprive that child of the effective enjoyment of rights granted to him or her under Union law.42
The recurring references in the case law to ‘substantial rights’ and ‘deprivation of enjoyment’ of rights resonates with the language that the Court would employ in the substance of rights-doctrine which was about to ensue.
2.2 The Initial Art. 20 TFEU Cases: A Fundamental Status Unleashed (2010–2011)
The Rottmann judgment was delivered by the Court in early 2010.43 In hindsight, the case revealed very little of the forceful doctrine that would emerge from it, but it held the key to unlocking the jurisdictional frontier of art. 20 TFEU. It was instantly clear that the case was a significant judgment for discerning the limits between purely internal situations in the Member States, the reach of Union law as regards domestic nationality law, and the role that Union citizenship might play in that.44
The main issue in Rottmann was whether Union citizenship could remedy against the individual’s risk of statelessness; thereby affecting the Member States’ competence in the area of nationality law.45 The conclusion was that, while statelessness in itself was not remedied directly under Union law, the risk of formally losing the status of Union citizenship as a consequence of that the Member State of nationality withdraws its naturalisation decision, brought the case immediately within the scope of application of art. 20 TFEU.46
It was not difficult for the Court to motivate why the Rottmann case was not a purely internal situation to domestic law. The 1992 Micheletti case had already established that the Member States’ competence in the sphere of nationality law had to be exercised with due regard to their obligations under Union law.47 The Member States nationality laws are after all the “ultimate ‘gates’ to Union citizenship and its rights”.48 As a consequence, the act of removing Member State nationality put the individual at risk of being “deprived of the rights attached” to the status of Union citizenship.49 While, in 2010 it was not yet clear, how far-reaching the Member States’ obligation to respect the risks associated with such de jure loss of Union citizenship should go, the case law on Union citizenship preceding Rottmann had made two things clear.
First, Union citizenship, by this time, was established as the intended fundamental status of the Member State nationals.50 Loss of Union citizenship therefore meant loss of something more substantial than just the loss of nationality of a particular Member State.51 Inevitably, once the Court started to affirm Union citizenship as the fundamental status of the nationals of the Member States, it was only a matter of time before it would have to address how free the Member States actually were in granting or withdrawing this fundamental status from an individual.52
Second, the important cross-border element for triggering the applicability of free movement law had already been reconfigured in light of Union citizenship. Cases like Zhu and Chen, Schempp, and Garcia Avello had placed the individual Union citizen at the centre of the legal reasoning, letting the finding of an actual exercise of freedom of movement hang in the periphery, but triggering the scope of Union law.53 The cross-border aspect of Zhu and Chen relied on the particularity of Irish nationality law being applicable also to children born in Northern Ireland, while the latter is technically a part of the United Kingdom and thus, another Member State than Ireland.54 Both Schempp and Garcia Avello lacked an actual use of freedom of movement by the Union citizens at the centre of the case, but the cross-border effect was triggered by, in Schempp’s case, someone else’s exercise of freedom of movement, and, in Garcia Avello, the fact of two children being born into having dual EU Member State nationalities.55
Therefore, at the time of the Court’s judgment in Rottmann, the status of Union citizenship was already developing its own jurisdictional test by stretching the scope of art. 21 TFEU to the limits of what could be considered exercise of freedom of movement. In addition, art. 21 TFEU had explicitly been made relevant for a Union citizen’s legal relationship with his or her home Member State in cases of discriminatory treatment for being “a mover”, or for keeping family reunification rights incurred through the use of freedom of movement intact upon a return to the Member State of nationality.56 Inevitably, the legal reasoning would at some point have to leave art. 21 TFEU altogether, and instead enter into the sphere of the status of Union citizenship itself, in art. 20 TFEU.57 As Union citizenship is not a status acquired through the exercise of freedom of movement, but prior to it, and since there is no autonomous way of acquiring or losing Union citizenship outside of the Member States’ respective nationality laws, the issue of withdrawing nationality had to be treated under art. 20 TFEU.58
The Rottmann judgment established a new jurisdictional frontier of Union law, the Court concluded that it was, however, not incompatible with art. 20 TFEU, read together with the principle of proportionality, for a Member State to withdraw a decision of naturalisation, after it transpires that the individual has obtained naturalisation based on fraudulent information.59 This way, the Court did not take a clear stance against statelessness as such, even when it is the consequence of the interaction of two Member States’ respective nationality regimes.60 It was deplored by some that the Court opted for a proportionality assessment, rather than seizing the opportunity of asserting human rights standards in this area as an integral part of Union citizenship.61
In his Opinion in Rottmann, AG Poiares Maduro had pointed out another aspect of the quality to a person’s identity that the status of Union citizenship holds. Within that quality, is the element of legal space; a specific territory where the status of Union citizenship takes effect. Union citizenship “does not require the existence of a people, but it is founded on the existence of a European political area from which rights and duties emerge”.62 For the individual to be within this area, was just as essential as it is to have the status of Union citizenship itself, in order to enjoy the additional quality that the status of Union citizenship brings to the nationals of the Member States. Enter Ruiz Zambrano.
While Rottmann concerned the issue of formal (de jure) loss of the status of Union citizenship and its attached rights, Ruiz Zambrano, and its many following judgments, has dealt with the issue of effective (de facto) deprivation of the enjoyment of the substance of Union citizenship rights.63 The latter caused by the individual Union citizen’s imminent risk of a forced departure from the Union’s territory.
Preceding Ruiz Zambrano were cases regarding family reunification rights, such as Carpenter and Zhu and Chen, where an only tenuous cross-border element linked the applicants to freedom of movement. The Ruiz Zambrano judgment was however the first family reunification case to outright do away with a connection to freedom of movement for ensuring residence rights of a Union citizen’s family members.64 AG Sharpston in her Opinion had argued for seeing two separate rights within art. 21 TFEU, a right to move, and a right to reside, the second one thus available also in a home Member State, but the Court made no brushstrokes towards freedom of movement in its reasoning.65 Placed firmly outside the realms of freedom of movement, it was, as in Rottmann, the added substance that the status of Union citizenship brings to an individual’s legal standing, which was at stake in Ruiz Zambrano. In its exceptionally short ruling, the Court relied on the well-established formula of Union citizenship as intended to be the “fundamental status” of Member State nationals and paired this with its recent judgment in Rottmann, to motivate solving the case solely within art. 20 TFEU.
The impossible situation that presented itself in Ruiz Zambrano was that of a family where TCN parents with no legal right to reside in the home Member State of their children, and no means to provide for them either. Could freedom of movement ‘save them’?66 Probably not, since the parents did not have the sufficient resources to establish themselves in another Member State so as to derive residence rights from their children à la Zhu and Chen.67 Nevertheless, the Court argued that the issuing of both residence and work permits to the Zambrano children’s father were a legal necessity. If not, the children risked being forced to leave the Union, and de facto be deprived of, the genuine enjoyment of the substance of the rights granted to them by their Union citizenship.68
The actual content of the ‘substance of rights’ was however far more abstract compared to the rights protection in earlier free movement cases concerning children. The right to reside and right to access to education that had been protected under Union law for the respective children in Baumbast, Zhu and Chen, and Ibrahim and Teixeira, concerned legal rights that were being effectively enjoyed in a host Member State.69 In Ruiz Zambrano, the children were not (yet) in active enjoyment of any rights granted under Union law. Rather, it was the potential of one day making use of freedom of movement, and possibly other Union citizenship rights, that motivated why their status as Union citizens should protect them from a Member State measure that obliged them to leave the legal territory where those rights may be realised.70
Similarly to Rottmann, the Ruiz Zambrano case reflected only a half-attempt of making Union citizenship into a guarantor for fundamental human rights. Rottmann had only indirectly dealt with the international law protection against statelessness, and the issue in Ruiz Zambrano could be linked to the human right to enter and to not be deported from your own state of nationality.71 However, both judgments filtered those international law standards through the particular lens of Union citizenship. Without making either judgment into an outright human rights case, they would both create its own take on these fundamental rights as an adapted feature of Union citizenship. Rottmann, in setting some safeguards, not directly against statelessness, but against the loss of the added value of Union citizenship; and Ruiz Zambrano, in letting the status of Union citizenship protect, not against deportation from a state of nationality, but from being forced to leave the Union as a whole. The Ruiz Zambrano case, much due to its enigmatically short judgment, opened a Pandora’s box of speculation of whether there from now on were no purely internal situations at all in EU free movement law.72 Its immediate aftermath would reveal it to be a doctrine of only exceptional applicability, rarely to be invoked successfully. In more recent case law however, the assessment model of art. 20 TFEU has progressively been streamlined to that of freedom of movement under art. 21 TFEU.73
2.3 The Dwelling Years: A Fundamental Status Reigned-In (2011–2015)
In the immediate aftermath of Ruiz Zambrano came a series of family reunification cases dealing with the newly formulated substance of rights doctrine.74 While not going back on the assertion of the new jurisdictional frontier that the substance of rights doctrine had established, the Court in these cases was focused on the limits to the doctrine’s scope of application, and highlighted the exceptionality of its relevance, to the point that it would be criticised as a too facts-specific and circumstantial approach.75
The first follow up cases to Ruiz Zambrano focused on containing the substance of rights doctrine to ‘very specific situations’.76 The case law quickly dropped the reference to the fundamental status of Union citizenship, and instead, opted for underlining the intrinsic connection to the exercise, or effective access to the possibility of enjoyment of freedom of movement, as being the real rationale for derived residence rights for family members under Union law.77
In McCarthy, the Court reasoned that there can be no derived right of residence for a TCN family member if there is neither an effect of impeding a Union citizen’s exercise of freedom of movement (art. 21 TFEU), nor a deprivation of that Union citizen’s genuine enjoyment of the substance of the rights conferred by the status of Union citizenship (art. 20 TFEU).78
A few months later, in Dereci, the Court asserted that art. 20 TFEU generates family reunification rights only “exceptionally”, if freedom of movement could not apply, and if there was a relationship of dependency of the Union citizen on the TCN family member.79 It highlighted that the mere ‘desirability’ of keeping ones family life within a particular Member State was not enough to live up to this threshold of ‘dependency’.80
The Court in Dereci also set another firm limit to the substance of rights-doctrine. It found that EU fundamental rights guarantees, as encoded in the Charter, could not be triggered to protect the right to respect to family life, unless there was first a finding that the Union citizen risked deprivation of the genuine enjoyment of the substance of Union citizenship rights.81 Fundamental rights in and of themselves, were therefore not an integral part of the substance of rights to which the doctrine referred. This was the Court’s first real confrontation with what AG Sharpston had argued in her Opinion in Ruiz Zambrano; namely that there should be some clear conditions set up for when EU fundamental rights protection could be triggered even in purely internal situations, so as to alleviate the adverse effects of reverse discrimination in this area.82 However, the result of the Court’s reasoning; that only if there is first a clear interference with art. 20 TFEU, will the Charter be triggered, would leave this reverse discrimination-conundrum unresolved.
Ensuing cases Iida, Ymeraga, and Alokpa confirmed the limits to the applicability of art. 20 TFEU for family reunification, without necessarily adding more definitions to the material content of the substance of rights-doctrine.83 These three cases highlighted some components for the jurisdictional and material relevance of the substance of rights-doctrine, all of which have been challenged by the more recent case law.
First, that there is an intrinsic connection between freedom of movement and art. 20 TFEU; which motivates why residence rights should foremost be derived directly from free movement law.84 The substance of rights-formula is only available “exceptionally” in “very specific situations” when neither secondary legislation, nor art. 21 TFEU can grant residence rights.85
Second, that Art. 20 TFEU is generally only relevant in the Union citizen’s home Member State, understood as his or her Member State of nationality. A Union citizen who is in a host Member State should instead return to their home Member State and there rely on art. 20 TFEU for asserting a derived residence right to a TCN family member.86 Art. 20 TFEU can therefore not be relied upon to avoid the requirement of having sufficient resources for not becoming a burden on the host Member State’s finances of Directive 2004/38.87
Finally, that the Charter does not apply for review of a Union citizen’s fundamental right to respect for family life (art. 7 CFR), if there is not already an established finding in the case that the effectiveness of Union citizenship under art. 20 TFEU is at risk.88
The Alokpa case of 2013 closed the curtain on a mini-streak of cases on the substance of rights doctrine, leaving many EU lawyers dismayed with the result.89 It was unsatisfactory that the doctrine generated new kinds of purely internal situations, now under art. 20 TFEU’s elusive criteria of ‘dependency’ and the ‘deprivation’ effect within the Union citizen’s home Member State; letting the jurisdictional scope of EU law vary in a manner as circumstantial as the elastic cross-border element had become in free movement law, and generating a new basis for legal inequality between Union citizens.90
2.4 Towards a Substantiated Union Citizenship Status (2016–Present)
As from 2016 and onwards, both the fundamental status of Union citizenship, and the substance of rights-doctrine have jointly returned in the language of a string of cases. The doctrine’s material consequences have developed in a manner that, contrary to the earlier tendency, has approximated art. 20 TFEU to the Charter’s fundamental rights guarantees and the realms of art. 21 TFEU in new ways. While the Court, in the early cases following Ruiz Zambrano, appeared focused on setting the limits to the scope of application to the substance of rights doctrine, it has, in the last part of this recent decade, added more workable definitions for its relevance.
First, in the Rendón Marín and CS cases in 2016, the Court’s reasoning brought the Rottmann and Ruiz Zambrano strands of the doctrine more closely together. Second, starting with Chavez-Vilchez, the case law has displayed a more generous model of assessment of the doctrine’s dependency criterion, which in itself integrates a consideration of the Charter’s fundamental rights standards.91 Thereby, a sought-after strengthening of the link between the substance of rights doctrine and family life protection as a fundamental right has been made, albeit without a clear pronunciation of art. 7 CFR as included in the ‘substance’ of the Union citizenship rights that the doctrine refers to.92
Rendón Marín and CS
With varying factual circumstances, the main question of both Rendón Marín and CS was the same: does the protection of residence rights derived under the substance of rights-doctrine of art. 20 TFEU allow for derogations, or is residence on that basis an ‘absolute’ right?93 The questions arose in both cases due to the fact that TCN primary caregivers of Union citizen children, had been refused continued residence in the relevant Member State as an automatic consequence of their criminal records. In an actual free movement situation, such national measures to expel a TCN family member of a Union citizen would have been reviewed under art. 27 and 28 of Directive 2004/38, in terms of being an interference with freedom of movement. However, concerning the withdrawal of residence rights of a TCN family member whose situation comes within the protective scope of the substance of rights doctrine, there had not yet been any judicial or legislative development on whether there were any lawful derogations available.
In his joint opinion in the two cases, AG Szpunar took stock of the developments to date of the substance of rights doctrine. He firstly highlighted that none of the de facto deprivation type cases following Ruiz Zambrano had dealt with the question of lawful derogations to the substance of rights doctrine, but the Rottmann case had; in dealing with de jure loss of Union citizenship.94 He argued that Rottmann and Ruiz Zambrano, although using different phrasing, had essentially concerned the same thing: the risk of total deprivation of Union citizenship rights.95 One concerned the de jure loss of the status of Union citizenship, and the other concerned the de facto loss of the possibility to enjoy that status and its attached rights. The AG could therefore argue that the Court’s reasoning in Rottmann on legitimate and proportionate derogations from ensuring the status of Union citizenship, especially in light of criminal conduct, could be transposed to the Ruiz Zambrano-like situations concerning residence rights. It could indeed be lawful to deny or withdraw residence rights that a TCN family member derived from a Union citizen under art. 20 TFEU, so long as the assessment preceding that measure took account of the principle of proportionality. The fact that such a measure would result in a Union citizen’s de facto deprivation of Union citizenship rights, would have to be weighed against the interest of forcing an expulsion of the TCN family member upon whom a Union citizen has a strong dependence.96
In its judgments in Rendón Marín and CS, the Court did not explicitly put situations of de jure and de facto loss of the status of Union citizenship and its attached rights on a par, but it incorporated the Rottmann principle of proportionality to an evaluation of measures derogating from residence rights derived from a Union citizen under art. 20 TFEU. This came about via the Court’s explicit transposal of the Directive 2004/38’s standards for what can be considered legitimate and proportionate derogations from free movement rights, to apply to rights incurred via the substance of rights doctrine. This assimilation of expulsion standards from the Directive to the substance of rights doctrine was partly made by the Court highlighting the doctrine’s ‘intrinsic connection’ to freedom of movement, thereby uniting the concept of acceptable derogations to all legal routes to TCN family members’ derived residence rights in Union citizenship and free movement law.97
Rendón Marín and CS represented a sound development of the substance of rights doctrine. To streamline the accepted derogations from the residence rights of Directive 2004/38 to those of art. 20 TFEU ensured more consistency for TCN family members’ derived residence rights from Union citizens. It also ensured that Union citizens exercising freedom of movement under Directive 2004/38, would not be more easily deportable, than a TCN who derived residence rights from the substance of rights doctrine; an adverse mosaic of law that the Court could hardly have tolerated. While confirming that Union citizens may lawfully de facto be deprived of the ‘substance’ of Union citizenship rights,98 it made the two strands of Art. 20 TFEU case law more tightly knit, to the benefit of material clarity. From here on, Rottmann and Ruiz Zambrano both essentially represent the Union citizen’s right to, neither de jure, nor de facto, be deprived of the substance of the rights conferred by Union citizenship, unless legitimate and proportionate derogations apply.
However, other questions remained. AG Szpunar had argued that the fundamental status of Union citizenship, and the core rights that the substance of rights doctrine serves to protect, should only be derogated from in accordance with the same standard for derogation that the Charter allows for limiting its stated fundamental rights (art. 52(1) CFR).99 If the Court were to take that leap, and assimilate the “substance” of rights of Union citizenship to the “essence” of fundamental rights protected by the Charter, it would truly be a revolutionary judicial development. To derogate from the Union citizen’s genuine enjoyment of the substance of the rights conferred by that status, would then be the same as to derogate from the fundamental rights that the EU legal order protects through its Charter.100
The Court has so far refrained from such a reasoning. The Charter’s codifications of the fundamental right to respect for family life (art. 7 CFR) and protection of the child’s best interest (art. 24(2) CFR) were only referred to in Rendón Marín and CS as they already make part of the proportionality assessment that a Member State must make before taking expulsion measures on grounds of public policy and public security in Directive 2004/38.101 The jurisprudence has anyhow opened up for further approximation of the substance of rights doctrine to the Charter. In the following case of Chavez-Vilchez, these two particular fundamental rights would, as a new development, be incorporated in the very assessment of whether a child’s dependence on a TCN primary caregiver is of such a nature to oblige the child to leave the EU, if that caregiver is denied residence rights.
In the Chavez-Vilchez judgment, the Court took a novel, generous approach to the notion of dependency, for triggering the substance of rights doctrine.102 In the formulation of the doctrine’s applicability, the Court however still highlighted that it could only concern “very specific situations”.103 The case compiled a string of appeals by TCN mothers in the Netherlands, who were primary caregivers of children with Union citizenship. Most of the appeals hung on the applicability of art. 20 TFEU for triggering legal residence for the mothers. The Dutch authorities had taken the strict approach that since the children concerned had Union citizen fathers, who could potentially take over the caregiving of the children if the mothers left the Union, the children’s substance of rights stemming from Union citizenship would not be at risk. The Court rejected this approach, finding that even if there is a Union citizen caregiver in the picture, there might still be such a relationship of dependence between the child and its TCN primary caregiver, that it triggers protection under art. 20 TFEU.104 According to the Court, it necessitated an individualised assessment of whether the child’s dependency on the TCN caregiver is of such a nature, that the child would be obliged to leave the territory of the EU if that caregiver was refused a right of residence.105 Relevant factors to consider were the extent of the child’s legal, financial, and emotional dependence on the primary caregiver.106 For this assessment, the Court referred to the fundamental rights of art. 7 and 24(2) of the Charter, which it, in Rendón Marín and CS, had found to be applicable when a Member State takes a measure of derogating from residence rights granted under art. 20 TFEU.107 However, in Chavez-Vilchez, protecting the right to family life, as well as the child’s best interest was said to be necessary to consider in the very assessment of the child’s dependence on their TCN parent. Contrary to the pronounced state of law in Dereci and Iida, the Charter should now be applicable to the legal assessment even before having established whether there was a Member State interference with art. 20 TFEU.108 From here on, the Court’s approach to art. 20 TFEU has been one of giving it increased material and jurisdictional relevance.
3 Broadening the Applicability of the Substance of Rights Doctrine
The most recent developments in the case law on the substance of rights doctrine reflect a progressive maturing of its sphere of application, material relevance, and assessment criteria. While the doctrine still only applies in “very specific situations”,109 and several aspects of its legal content and effect remain unanswered,110 the jurisprudence as a whole is gaining in substance and approaching the jurisdictional scope of freedom of movement itself.
3.1 Adding Definitions to the Dependency Test of the Doctrine
The K.A. and Others case from 2018 concerned an assembly of appeals from Belgium.111 The respective applicants in all of the seven cases were subject to return decisions and re-entry bans. They were all TCN family members of Union citizens with Belgian nationality, who had never made use of freedom of movement. Varyingly, the Union citizens concerned were minors or adult family members to the TCN applicants. Similar to Rendón Marín, the Court reasoned that if there is a risk that a Union citizen will be forced to leave the EU because of their dependence on a TCN family member, the former thus being deprived of their substance of rights as Union citizens, this risk must be assessed, and weighed against the reasons for imposing the return decision and entry ban on the TCN.112 In addition, there was an obligation on the Member States to examine a residence application based on art. 20 TFEU from a TCN applicant, regardless of when and from where it is submitted, and regardless of the point in time the relationship of dependency has arisen.113
For children, the standard developed in the Chavez-Vilchez case applies, where the dependency assessment should consider “who has custody of the child and whether that child is legally, financially or emotionally dependent on the third-country national parent”.114 As in Chavez-Vilchez, such dependency assessments must duly consider the fundamental rights standards of art. 7 and 24(2) CFR. Regarding Union citizens who are adults, the Court made clear that the threshold is high for the substance of rights doctrine to extend residence rights for a TCN family member. Generally, none of the appeal cases in K.A. and Others that concerned adult relationship, appeared to reach that threshold, as it was not likely that the adult Union citizens would be compelled to depart from the EU as a result of the TCN family member having to leave. Only in “exceptional cases” where “no form of separation” between the adult Union citizen and the TCN may be possible, could that threshold of dependence be reached.115
The Ciudad Real case from 2020 added even more to the understanding of the dependency requirement between adults.116 The core aspect of dependency in adult family relationships is not fulfilled by the fact that there may be a legal obligation in national law for spouses to live together, since that requirement could not legally compel the Union citizen to leave the territory of the Union.117 The dependency criterion instead pivots on a factual circumstance of whether the adult Union citizen has a free choice or not whether to stay or leave the Union. Whereas minors are assumed to naturally be obliged to leave the Union with a TCN primary caregiver upon whom they depend, the adult Union citizen’s protection under the substance of rights doctrine turns on whether their dependency on a TCN family member is such as to take away their freedom to choose.118
3.2 The Substance of Rights Doctrine Taking Extra Territorial Effect
The Tjebbes case from 2019 echoed the issues of Rottmann concerning de jure loss of the status of Union citizenship.119 However, in Tjebbes, the loss of Dutch nationality endured by the various applicants was not the result of an active measure of withdrawal of that nationality from each individual concerned. Rather, it was the result of an automatic operation of a Dutch law where Dutch nationality ‘expired’ for adult nationals of dual nationality, who, among other criteria, had spent ten uninterrupted years residing outside of the Netherlands, and outside of the territory of the European Union. None of the applicants had resided somewhere within the EU for a long time, if ever. Both in law and in fact were the applicants far removed from an EU free movement situation.
According to the Court’s reasoning, it did not matter that the applicants were all domiciled outside of the EU Member States, and that they now all had non-EU nationalities – thereby not risking statelessness. Art. 20 TFEU took extra-territorial effect on the legal relationship between a former national outside of the Union and a Member State, and applied to the appeals for regaining Dutch nationality.120 By reason of its “nature and its consequences” the matter of such an automatised loss of Union citizenship as an effect of Dutch domestic law, came within the scope of application of Union law.121 It was highlighted that the proportionality assessment should include a consideration of whether the withdrawal of Member State nationality would ‘disproportionately affect the normal development of his or her family and professional life from the point of view of EU law’, linking the assessment to regard of the fundamental rights standards of the Charter, in particular art. 7 and 24(2).122
3.3 Article 20 TFEU Reaching beyond the Home Member State
While the initial substance of rights cases like Rottmann, and Ruiz Zambrano, dealt with the home Member State’s obligation to not deprive its own nationals of the genuine enjoyment of the substance of rights of Union citizenship,123 the more recent judgment in JY affirmed that art. 20 TFEU may be relevant also to a host Member State, and in clear instances of active use of freedom of movement.124 In JY, which concerned a Union citizen caught in a situation of statelessness, when seeking to naturalise in her host Member State, art. 20 TFEU was simultaneously applicable to both the home and host Member State of the applicant, and took effect before art. 21 TFEU, despite a clear cross-border element in the case. Such application of art. 20 TFEU to a situation with an active use of freedom of movement narrows the difference between a measure that should be considered a restriction under art. 21 TFEU, or a deprivation under art. 20 TFEU.125 JY, following the Rottmann and Tjebbes type cases of de jure deprivation of the status of Union citizenship, placed a clear onus on the Member State to which the Union citizen had exercised the right to free movement; the host Member State to ensure the effectiveness of art. 20 TFEU. The applicant’s enjoyment of the status of Union citizenship was at risk as the consequence of the host Member State’s decisions during the course of a naturalisation process. The Court found that when the Union citizen has renounced her first nationality from her original home Member State; thus, temporarily lost her status of Union citizenship; it would be disproportionate of the host Member State to revoke a decision of assurance of prospective naturalisation, with the effect of causing the permanent loss of the individual’s status of Union citizenship, thereby losing the enjoyment of all of her Union citizenship rights.126 In a legal landscape where art. 20 TFEU would apply to a situation where a Union citizen had not made use of freedom of movement but risked being deprived of the enjoyment of the substance of his or her Union citizenship rights, art. 20 TFEU must certainly be applicable to a situation of actual use of freedom of movement where the Union citizen concerned risks deprivation of all of those rights.127
The delimitation between art. 21 and 20 TFEU has then become an issue of weighing options, rather than following a dictum that freedom of movement should always overtake the relevance of the substance of rights-doctrine.128 In addition, and following the streamlined approach to derogations to either de jure and de facto loss of Union citizenship rights, the Court in JY referenced Rendón Marín for reasserting the premises for the proportionality assessment.129 And, with a nod to Tjebbes, affirmed that a measure that causes de jure loss of Union citizenship must have due regard of the Charter’s fundamental rights, in particular the respect of private and family life of art. 7 CFR and; to the extent that the decision affects children, also art. 24(2) CFR.130
4 Towards a Streamlined Approach to Art. 21 and Art. 20 TFEU
At the time of delivery of the Rottmann and Ruiz Zambrano judgments at the start of the 2010’s, there was little anticipation that the dividing line between freedom of movement – with its exigence on, even just a slight, cross-border element – and the newly shaped substance of rights doctrine would become problematic. The Union citizenship cases that had come out in the early 2000’s had motored a rights-driven approach, often protecting the individual Union citizen over broader integrationist aims.131 Therefore, it did not seem far-fetched that the fundamental status of Union citizenship could in time result in a unified approach to protecting rights attached to the personal scope of Union citizenship, regardless of whether the individual’s case came under art. 21 or art. 20 TFEU, or whether the provisions of Directive 2004/38 were at issue.132 However, the first half of the last decade saw a legal development of fragmentation of the rights available to Union citizens under the Directive,133 under art. 21 TFEU,134 or under the status of Union citizenship under art. 20 TFEU.135 With regards to EU fundamental rights review, it is yet to be seen that the personal scope of civis europeaus sum would be enough for an individual Union citizen to assert a coherent fundamental rights standard across the European Union territory.136 In the recent half of the last decade, some steps that are in line with that ambition can be noted. The home vs. host Member State dichotomy has outlived its purpose as a jurisdictional boundary for art. 20 TFEU and should be done away with so as to move towards a more coherent web of EU fundamental rights review across free movement situations and a substantiated status of Union citizenship.
4.1 Activating the Scope of the EU Charter of Fundamental Rights
Progressively, the case law is moving towards a unified approach of reviewing the Member States’ derogations from the effectiveness of either art. 21 TFEU or art. 20 TFEU, as both instances activate EU fundamental rights standards and the principle of proportionality.137 Some argue that the substance of rights doctrine is redundant, since what it protects; essentially the future exercise of free movement rights; is already protected vis-à-vis both host and home Member State through art. 21 TFEU and its restrictions-approach.138 The distinction between whether, and in what order, an assessment should foremost be made under Directive 2004/38, or under art. 21 TFEU, or art. 20 TFEU, is however still relevant both for discerning when the Directive’s economic conditions for residence rights are to be imposed,139 whether there is an alternative domestic legal ground for residence rights,140 or for establishing when a dependency-assessment of a family relationship should be made.141 For example, in the recent CG case, a last layer of protection of art. 20 TFEU would have been pertinent, if the family concerned had not been able to claim a right of residence based on national law, which, circumstantially, brought them within the protective scope of art. 21 TFEU.142
To maintain the only ‘supplementary’ nature of art. 20 TFEU for a Union citizen in an actual free movement situation, as the substance of rights doctrine confines its applicability to only “very specific circumstances” might generally be a reasonable approach. However, in some cases, it is questionable why art. 21 TFEU should as a rule overtake the relevance of art. 20 TFEU. Cases in point are those on extradition of Union citizens from the Union to a third state, such as Petruhhin, and BY.143 Here, although the measure in practice would involve a forced departure of the person from the territory of the Union, the Court chose to deal with the issue as a restriction to art. 21 TFEU, rather than a de facto deprivation of rights under art. 20 TFEU.144 That approach might make sense if maintaining that the substance of rights doctrine should be subsidiary to freedom of movement.145 However, given that the proportionality assessments tend to be more individualised under the substance of rights doctrine, and more abstract under the restrictions approach, the question of whether art. 20 TFEU would have been available in Petruhhin and BY as a last resort applicable to the host Member State if the restriction-test of art. 21 TFEU had not yielded result in terms of legal protection is an important one to answer.146 An increased use of art. 20 TFEU also in relation to a Union citizen’s host Member State, would arguably bring more substance to the status itself of Union citizenship, making it independently operational whatever the free movement situation in a case may be.
Additionally, as seen in the Bajratari case from 2019, regarding assessments of residence rights that turn on the concept of ‘sufficient resources’ of art. 7(1)(b) of Directive 2004/38, there is a considerable risk that the fundamental rights protection of children, whose enjoyment of rights are granted via the Directive will fall behind the fundamental rights standards that apply to children whose situation triggers a deprivation under art. 20 TFEU, or restriction under art. 21 TFEU.147 Chavez-Vilchez and K.A. and Others show that the substance of rights-doctrine now integrate the Charter’s standards for a right to family life and the child’s best interest into the assessment of whether a minor Union citizen is at risk of being deprived of the effective enjoyment of their Union citizenship due to their dependency on a TCN primary caregiver.148 From the standpoint of a ‘fundamental status of Union citizenship’, it is inadequate that a Union citizen child whose residence right in a host Member State is assessed under Directive 2004/38 can only obtain review of their situation under the Charter if they first have sufficient economic resources to establish lawful residence.149 The children in the Bajratari case, whose family reunification rights with their TCN primary caregiver pivoted entirely on whether their economic resources were sufficient, were legally separated from the situation of the children in Chavez-Vilchez case only by the crossing of a border. It is difficult to reconcile that the children’s relationship to their caregiver in Chavez-Vilchez were individually assessed though the lens of art. 7 and 24(2) of the Charter, with how the Bajratari children’s family life was assessed only through a non-individualised reading of the economic conditions in Directive 2004/38. To distinguish a home and host Member State within the substance of rights doctrine generates similar problems of legal inequality as the blurry cross-border requirement has often done within freedom of movement.
The CG case from 2021 offered some remedy to this, as the Court affirmed an obligation on a host Member State to ensure a positive right for Union citizens to live in dignified conditions under art. 1 of the Charter. But this was only achieved by taking the matter out of the realms of Directive 2004/38, and into the primary law level of an interference with art. 21 TFEU.150 While the direct linking of fundamental rights to the status of Union citizenship remains controversial,151 it is imperative to streamline the access to fundamental rights review whether a Union citizen’s situation is assessed under the Directive 2004/38, or under art. 21 or art. 20 TFEU.
4.2 Equal Treatment and Economic Pre-conditions
While the ‘fundamental status’ of Union citizenship appeared as a mantra in many early equal treatment cases, the scope of application and content of the right to equal treatment has in the last decade been largely absorbed by the pre-conditions of Directive 2004/38.152 The substance of rights-doctrine lives its own life in parallel to this, as it does not contain any economic pre-conditions for deriving residence rights of economically inactive TCN family members.153 Thereby, their equal treatment rights under art. 20 TFEU may be materially wider, as including social assistance and study maintenance grants, than what Directive 2004/38 would allow for.154
The Court’s reasoning in the CG case slightly abridged this asymmetrical fundamental rights protection. In CG, the economic conditions for residence rights of Directive 2004/38 were not fulfilled, but national law in the host Member State had nevertheless provided the Union citizen concerned with a right of residence. Echoing Sala, the Court thereby found application of Union law based directly on the Union citizen’s lawful exercise of the right to freedom of movement under art. 21 TFEU, triggering the right to equal treatment in art. 18 TFEU.155 In turn, the review of any interference with these primary law provisions activated the application of the Charter’s special legal protection of children under art. 7 and 24(2) CFR, and the right to live in dignified conditions under art. 1 CFR.156
For residence rights based on Directive 2004/38, the demand for self-sufficiency is a pre-condition for the enjoyment of rights, as evident from the case law on the interpretation of art. 7(1)(b) of Directive 2004/38.157 However, any other legal basis for lawful residence placed the individual directly within the scope of art. 21 and art. 18 TFEU, and the fundamental rights protection of the Charter, regardless of their economic situation. Similarly, for the purpose of relying on art. 20 TFEU, the Member State’s demand for self-sufficiency was not accepted by the Court in Ciudad Real as a legitimate derogation to a derived residence right of a TCN family member based on the substance of rights-doctrine. This was so, as it would interfere with the effectiveness of Union citizenship under art. 20 TFEU and compromise the enjoyment of the fundamental right to respect for family life under art. 7 of the Charter.158 While the threshold for applicability of art. 20 TFEU is much higher compared to that of Directive 2004/38, its individualised fundamental rights review under Union law are immediate. The result of seeing art. 20 TFEU as subsidiary to freedom of movement, whether exercised under the Directive 2004/38, or directly under art. 21 TFEU, is therefore peculiar, in that Union citizens in a free movement situation will in some instances have less direct fundamental rights protection under Union law than those who stay at home.
The dilemma here hangs on that a Member State of nationality cannot absolve themselves of a social responsibility of its own nationals.159 For the home Member State, the Court has made clear that the effectiveness of Union citizenship knows no price, or rather, may not be framed as an ‘unreasonable burden’.160 This comparative downgrade of the sort of protection that Directive 2004/38 may generate for Union citizens and their family members compared to those Union citizens who stay at home, is unsustainable with the fundamental status of Union citizenship as well as with the importance of a well-functioning free movement of persons regime.
While it is difficult to establish when a national measure is foremost a restriction to freedom of movement, and when it is foremost a deprivation of the enjoyment of Union citizenship rights, the view that only the home Member State should have obligations under art. 20 TFEU will not help to resolve that. Firstly, it is not always evident which Member State that is a home, and which is host, and several Union citizens will have ties to more than two EU Member States. Secondly, since art. 21 TFEU evidently may apply to the Member State of nationality, i.e.; the right to exit, and for circular migration in the EU, it is easily conceivable, as was implied already in Rendón Marín, NA, and Alokpa, that art. 20 TFEU would apply also to a host Member State, whose measures risk de facto to deprive an individual of his or her enjoyment of the substance of Union citizenship rights, but where living in the Member State of nationality is not possible.
5 Conclusion: An Unfolding Destiny
The continuous, albeit winding development of art. 20 TFEU in the Court’s case law signals that the vision of civis europaeus sum is not forgotten.161 However, it is a counterintuitive aspect of the fundamental status of Union citizenship, that it presently enjoys more fundamental rights protection through assessments made under the substance of rights doctrine, than under secondary free movement law itself. A firm judicial step should be taken with regards to streamlining the access to fundamental rights review under the Charter in family reunification cases, regardless of whether they are based on Directive 2004/38, art. 21 TFEU or art. 20 TFEU. A Union citizenship status of genuine substance is the suitable vehicle towards that.
Simultaneously, the substance of rights doctrine has a hard time recovering from the criticism of being too facts-specific and circumstantial in its application. Its high threshold of deprivation-effect, and relational ‘dependence’ forces national courts and authorities to tread into difficult assessments of just how much a child’s well-being depends on one particular primary caregiver, or just what kind of agency an adult Union citizen will have, to out of free choice stay or leave the Union without their TCN family member.162 Similarly, the duration of such derived residence rights, and what is to happen to the TCN once the dependency relationship no longer exists, remain unclear.163
While the real content in terms of ‘rights’ of the substance of rights doctrine is yet to be clarified, the doctrine’s undeniable forcefulness lies in its protection of the Union citizen’s retention of a pivotal legal status, and right to remain within a bounded legal space, where, in turn many, and various rights may be claimed or exercised under Union law.164 The substance of rights doctrine provides the canvas, rather than the content for the genuine enjoyment of Union citizenship rights. The de jure situations evenly disperse obligations under art. 20 TFEU to both home and host Member State, as shown in JY, but the family reunification cases have so far explicitly only allocated responsibility to the Member State of nationality to safeguard against the individual’s de facto loss of Union citizenship rights.165 Yet, both strands of the case law reflect the same right to neither de facto (loss of territory) nor de jure (loss of status) be completely deprived of Union citizenship rights. For an effective, streamlined and secure web of EU fundamental rights protection, the jurisdictional applicability of art. 20 TFEU should cover the integral territory of the EU, and not only take effect in the one or more Member States where the individual Union citizen holds nationality. After all, a situation of dependence between a Union citizen and a TCN family member might very well arise also in a Union citizen’s exercise of freedom of movement to a host Member State, in cases where a legal basis for family residence rights in Directive 2004/38 or under secondary legislation, or domestic law, might not be available.
The substance of rights doctrine emanates from the vision of the destined fundamental status of Union citizenship, which was firstly proclaimed in free movement law. It would be appropriate that the unfolding of this doctrine’s destiny would see it transcend both freedom of movement and the individual’s relationship to their home Member State and reach the same jurisdictional realms as freedom of movement itself.
Among a rich literature, see Alina Tryfonidou, The Impact of Union Citizenship on the EU’s Market Freedoms (Hart Publishing 2016), Francesco de Cecco, ‘Fundamental Freedoms, Fundamental Rights, and the Scope of Free Movement Law’ (2014) 15 German Law Journal 383, Ferdinand Wollenschläger, ‘A New Fundamental Freedom beyond Market Integration: Union Citizenship and Its Dynamics for Shifting the Economic Paradigm of European Integration’ (2011) 17 European Law Journal 1.
Niamh Nic Shuibhne, ‘Limits Rising, Duties Ascending: The Changing Legal Shape of Union Citizenship’ (2015) 52 Common Market Law Review 889, Anastasia Iliopoulou-Penot, ‘Deconstructing the Former Edifice of Union Citizenship? The Alimanovic Judgment’ (2016) 53 Common Market Law Review 1007, Eleanor Spaventa, ‘Once a Foreigner, Always a Foreigner. Who Does Not Belong Here Anymore? Expulsion Measures’ in Herwig Verschueren (ed), Residence, Employment and Social Rights of Mobile Persons: On How EU Law Defines Where They Belong (Intersentia 2016).
See Eleanor Spaventa, ‘Seeing the Wood Despite the Trees? On the Scope of Union Citizenship and Its Constitutional Effects.’ (2008) 45 Common Market Law Review 13, Camille Dautricourt and Sebastien Thomas, ‘Reverse Discrimination and Free Movement of Persons Under Community Law: All for Ulysses, Nothing for Penelope?’  European Law Review 433, Alina Tryfonidou, ‘Family Reunification Rights of (Migrant) Union Citizens: Towards a More Liberal Approach’ (2009) 15 European Law Journal 634.
Päivi Johanna Neuvonen, ‘EU Citizenship and Its “Very Specific” Essence: Rendón Marin and CS’ (2017) 54 Common Market Law Review 1201, and Stanislas Adam and Peter Van Elsuwege, ‘Citizenship Rights and the Federal Balance between the European Union and Its Member States: Comment on Dereci’ (2012) 37 European Law Review 176.
Francesca Strumia, ‘Supranational Citizenship’s Enablers: Free Movement from the Perspective of Home Member States’ (2020) 45 European Law Review 507.
On the minimalist approach adopted after the Ruiz Zambrano case, see Martijn van den Brink, ‘The Origins and the Potential Federalising Effects of the Substance of Rights Test’ in Dimitry Kochenov (ed), EU Citizenship and Federalism: The Role of Rights (Cambridge University Press 2017) p. 86. Arena talks of both an ‘expansive’ and a ‘reflective’ phase in the Court’s treatment of the substance of rights-doctrine, Amedeo Arena, ‘The Wall Around EU Fundamental Freedoms: The Purely Internal Rule at the Forty-Year Mark’ (2019) 38 Yearbook of European Law 153 p. 179 f. and p. 194 f.
Case C-34/09, Ruiz Zambrano, EU:C:2011:124, para 42 (emphasis added).
Kay Hailbronner and Daniel Thym, ‘Case C-34/09, Gerardo Ruiz Zambrano v. Office National de l’emploi (ONEm), Judgment of the Court of Justice (Grand Chamber) of 8 March 2011’ (2011) 48 Common Market Law Review 1253, Hanneke van Eijken and Sybe de Vries, ‘A New Route into the Promised Land? Being a European Citizen after Ruiz Zambrano’ (2011) 36 European Law Review 704, Stephanie Reynolds, ‘Exploring the “Intrinsic Connection” Between Free Movement and the Genuine Enjoyment Test: Reflections on EU Citizenship After Iida’ (2013) 38 European Law Review 376, Francesca Strumia, ‘Looking for Substance at the Boundaries: European Citizenship and Mutual Recognition of Belonging’ (2013) 32 Yearbook of European Law 432, Dimitry Kochenov and Richard Plender, ‘EU Citizenship: From an Incipient Form to an Incipient Substance? The Discovery of the Treaty Text’ (2012) 37 European Law Review 369.
Opinion of Advocate General Poiares Maduro in Case C-135/08, Rottmann, EU:C:2009:588, para 26.
Christina Neier, ‘Residence Right under Article 20 TFEU Not Dependent on Sufficient Resources: Subdelegación Del Gobierno En Ciudad Reals Case C-836/18, Subdelegación Del Gobierno En Ciudad Reals, Judgment of the Court of Justice (Fifth Chamber) of 27 February 2020, EU:C:2020:119’ (2021) 58 Common Market Law Review 549 p. 556, Strumia (n 5) p. 521 f.
Neier (n 10) p. 556, Strumia (n 5) p. 521 f.
Compare Case C-86/12, Alokpa and Moudoulou, EU:C:2013:645, para 33, Case C-115/15, NA, EU:C:2016:487, paras 71–81, and Case C-165/14, Rendón Marín, EU:C:2016:675, para 79.
Directive 2004/38/EC of the European Parliament and of the Council of 29 April 2004 on the right of citizens of the Union and their family members to move and reside freely within the territory of the Member States amending Regulation (EEC) No 1612/68 and repealing Directives 64/221/EEC, 68/360/EEC, 72/194/EEC, 73/148/EEC, 75/34/EEC, 75/ 35/EEC, 90/364/EEC, 90/365/EEC and 93/96/EEC (Text with EEA relevance) OJ L 158, 30.4.2004, pp. 77–123.
See Opinion of Advocate General Spzunar, Case C-93/18, Bajratari, EU:C:2019:512, para 86.
Case C-184/99, Grzelczyk, EU:C:2001:458, para 31. See van den Brink (n 6) p. 87 f.
The radical development of applying Union citizenship to a situation without any cross-border element in Ruiz Zambrano was criticized by Hailbronner and Thym (n 8).
A legal development that raised concerns of legal certainty and arbitrary outcomes, see Niamh Nic Shuibhne, ‘(Some of) The Kids Are All Right: Comment on McCarthy and Dereci’ (2012) 49 Common Market Law Review 349.
Charter of Fundamental Rights of the European Union OJ C 326, 26.10.2012, pp. 391–407.
Case C-274/96, Bickel and Franz, EU:C:1998:563, Case C-85/96, Martínez Sala v Freistaat Bayern, EU:C:1998:217.
Grzelczyk (n 15) para 31. See also Case C-413/99 Baumbast and R, EU:C:2002:493, para 82, Case C-200/02, Zhu and Chen, EU:C:2004:639, para 25. Case C-709/20, The Department for Communities in Northern Ireland (CG), EU:C:2021:602, para 62.
See Grzelczyk (n 15) paras 32–36.
Spaventa (n 3) p. 18–20. See earlier repealed secondary legislation: Directives 64/221/EEC, 68/360/EEC, 72/194/EEC, 73/148/EEC, 75/34/EEC, 75/35/EEC, 90/364/EEC, 90/365/EEC and 93/96/EEC.
Ibid. p. 23.
Grzelczyk (n 15) para 30. See more recently CG (n 20) para 63.
Opinion of Advocate General La Pergola in Case C-85/96, Martínez Sala v Freistaat Bayern, EU:C:1997:335, paras 18–19. See also Case C-369/90, Micheletti and Others v Delegación del Gobierno en Cantabria, EU:C:1992:295, para 10, and Case C-192/99, Kaur, EU:C:2001:106, para 19.
Stephen Hall, ‘Loss of Union Citizenship in Breach of Fundamental Rights’ (1996) 21 European Law Review 129.
Opinion in Martínez Sala (n 25) para 23.
Ibid. paras 18–20. See also Martínez Sala (n 19) para 61–63. Reaffirmed 2021 in CG (n 20) para 63.
Grzelczyk (n 15), Case C-456/02, Trojani, EU:C:2004:488, Case C-138/02, Collins, EU: C:2004:172.
Tryfonidou (n 1) p. 79–117. On the roles of the Advocates General in this regard, see analysis by Noreen Burrows and Rosa Greaves, ‘The Advocates General and the Concept of Citizenship’, The Advocate General and EC Law (Oxford University Press 2007). See Advocate General Geelhoed’s Opinion in Case C-413/99, Baumbast and R., EU:C:2001:385, para 92. See also de Cecco (n 1).
Martínez Sala (n 19) para 63, Grzelczyk (n 15) para 31, Trojani (n 29) para 40.
Case C-224/98, D’Hoop, EU:C:2002:432, para 35 (emphasis added).
Baumbast (n 20) para 84.
Opinion in Baumbast (n 30) para 53.
Ibid., para 63.
Ibid., para 110.
Ibid., para 126. Compare to the discourse on the “essence” of EU fundamental rights, Mark Dawson, Orla Lynskey and Elise Muir, ‘What Is the Added Value of the Concept of the “Essence” of EU Fundamental Rights?’ (2019) 20 German Law Journal 763.
Baumbast (n 20) paras 50–63.
Ibid., para 82, and paras. 50–63. See also Case C-490/20, Stolichna obshtina, rayon “Pancharevo” (VMA), EU:C:2021:1008, paras 58–62, and Case C-181/19, Jobcenter Krefeld, EU:C:2020:794. The protection of children has become increasingly prevalent in the case law, see Catherine Jacqueson, ‘A Resisting Enclave of Social Rights – Protecting the Children of Former Workers: C-181/19 Jobcenter Krefeld – Widerspruchsstelle v JD’ (2021) 28 Maastricht Journal of European and Comparative Law 731.
Baumbast (n 20) paras 71–75.
Ibid., para 65.
Ibid., paras 50–63, para 71.
Case C-135/08 Rottmann, EU:C:2010:104.
See Dimitry Kochenov, ‘Case C-135/08, Janko Rottmann v. Freistaat Bayern, Judgment of the Court (Grand Chamber) of 2 March 2010’ (2010) 47 Common Market Law Review 1831.
Rottmann (n 43) paras 34–35, and paras 52–54.
Ibid., para 42. A stance maintained in the recent Case C-118/20, Wiener Landesregierung (Révocation d’une assurance de naturalisation)(JY), EU:C:2022:34.
Micheletti (n 25), Rottmann (n 43) para 45.
Hanneke van Eijken, ‘Tjebbes in Wonderland: On European Citizenship, Nationality and Fundamental Rights: ECJ 12 March 2019, Case C-221/17, M.G. Tjebbes and Others v Minister van Buitenlandse Zaken, ECLI:EU:C:2019:189’ (2019) 15 European Constitutional Law Review 714 p. 3.
Rottmann (n 43) para 46 (emphasis added).
Ibid., para 43.
Opinion in Rottmann (n 9) para 23.
On the obligations of the Member State of nationality, see Strumia (n 5) p. 521 f.
Zhu and Chen (n 20), Case C-403/03, Schempp, EU:C:2005:446, Case C-148/02, Garcia Avello, EU:C:2003:539.
Zhu and Chen (n 20) paras 39–41.
Schempp (n 53) paras 23–25, Garcia Avello (n 53) paras 27–29.
D’Hoop (n 32), Case C-291/05, Eind, EU:C:2007:771.
Although, note the counter-arguments to the relevance of the substance of rights-doctrine put forward by Martijn van den Brink, ‘Is It Time to Abolish the Substance of EU Citizenship Rights Test?’ (2021) 23 European Journal of Migration and Law 13.
Regarding the scope of Union law in this respect, see Advocate General Szpunar’s Opinion in Case C-118/20, Wiener Landesregierung (Révocation d’une assurance de naturalisation)(JY), EU:C:2021:530, paras 53–70. Advocate General Poaires-Maduro had anchored the Rottmann case in freedom of movement, but had also, ultimately concluded it based on, what is now, art. 20 TFEU, Opinion in Case C-135/08, Rottmann (n 9) paras 11–14.
Rottmann (n 43) para 59. What van Eijken refers to as an ‘abstract’ proportionality test, van Eijken (n 48) pp. 9–11. See Opinion in Rottmann (n 9) paras 33–34.
See critique by Kochenov (n 44) pp. 1842–1845. p. 1837. On the problems of this abstract rather than individual assessment under the principle of proportionality, see van Eijken (n 48) pp. 9–12.
Kochenov (n 44) p. 1844.
Opinion in Rottmann (n 9) para 23. (emphasis added). On the concept of territory in Union citizenship law, see Loïc Azoulai, ‘Transfiguring European Citizenship: From Member State to Union Territory’ in Dimitry Kochenov (ed), EU Citizenship and Federalism: The Role of Rights (Cambridge University Press 2017) and Niamh Nic Shuibhne, ‘The “Territory of the Union” in EU Citizenship Law: Charting a Route from Parallel to Integrated Narratives’  Yearbook of European Law 1.
See case law development from Ruiz Zambrano (n 7) to Case C-836/18, Subdelegación del Gobierno en Ciudad Real, EU:C:2020:119.
See Case C-60/00, Carpenter, EU:C:2002:434, Zhu and Chen (n 20).
Opinion of Advocate General Sharpston in Case C-34/09, Ruiz Zambrano, EU:C:2010:560, paras 80–84. See also Opinion of Advocate General Sharpston in Case C-212/06, Gouvernement de la Communauté française and Gouvernement wallon, EU:C:2007:398, para 151.
The substance of rights-doctrine will normally not be engaged if the Union citizen can use freedom of movement to obtain family reunification, see Reynolds (n 8) p. 384.
Spaventa (n 3), Niamh Nic Shuibhne, ‘Free Movement of Persons and the Wholly Internal Rule: Time to Move On?’ (2002) 39 Common Market Law Review 731. For a definition of reverse discrimination, see Arena (n 6) p. 213.
Opinion in Ruiz Zambrano (n 65) para 44.
Baumbast (n 20), Zhu and Chen (n 20), Case C-310/08, Ibrahim and Secretary of State for the Home Department, EU:C:2010:80, Case C-480/08, Teixeira, EU:C:2010:83. See more recently Jobcenter Krefeld (n 39).
The potential use of freedom of movement had also motivated the outcome in Garcia Avello (n 53) para 36.
Respectively dealt with in International Law Instruments like the Convention on the Reduction of Statelessness of 30 August 1961 and the European Convention on Nationality, adopted by the Council of Europe on 6 November 1997, and Art. 3 of Protocol 4 to, the European Convention of Human Rights (‘the ECHR’).
Strongly criticised by Hailbronner and Thym (n 8).
On a similar point, see Hanneke van Eijken, ‘Connecting the Dots Backwards, What Did Ruiz Zambrano Mean for EU Citizenship and Fundamental Rights in EU Law?’ (2021) 23 European Journal of Migration and Law 48 p. 59.
Case C-434/09, McCarthy, EU:C:2011:277, Case C-256/11, Dereci and Others, EU:C:2011:734, Case C-40/11, Iida, EU:C:2012:691, Case C-87/12, Ymeraga and Ymeraga-Tafarshiku, EU:C:2013:291, Alokpa (n 12).
Nic Shuibhne (n 17) p. 378, Strumia (n 5) pp. 519–520.
Dereci (n 74) para 40, Iida (n 74) para 71, Alokpa (n 12) para 32.
See analysis by Reynolds (n 8).
McCarthy (n 74) para 53.
Dereci (n 74) para 67.
Ibid., paras 66–68. Reiterated in Case C-82/16, K.A. and Others, EU:C:2018:308, para 74.
Dereci (n 74) para 72.
Opinion in Ruiz Zambrano (n 65) paras 145–150. See Dereci (n 74) paras 66–67 and paras. 70 f.
Iida (n 74), Ymeraga (n 74), Alokpa (n 12).
Iida (n 74) para 72, Ymeraga (n 74) para 37, Alokpa (n 12) para 23.
Iida (n 74) para 71, Ymeraga (n 74) para 36, Alokpa (n 12) para 32. Reynolds (n 8) p. 390.
Iida (n 74) paras 76–77, Ymeraga (n 74) paras 39–45, Alokpa (n 12) paras 30–35.
Alokpa (n 12) paras 30–31 and 33–35.
Iida (n 74) paras 78–81, Ymeraga (n 74) paras 40–43.
See in general, Nic Shuibhne (n 17), Alina Tryfonidou, ‘Redefining the Outer Boundaries of EU Law: The Zambrano, McCarthy and Dereci Trilogy’ (2012) 18 European Public Law 193, Peter Van Elsuwege, ‘“The Phenomenon of Reverse Discrimination: An Anomaly in the European Constitutional Order?”’ in Lucia Serena Rossi and Federico Casolari (eds), The EU after Lisbon: Amending or Coping with the Existing Treaties? (Springer 2014).
Dimitry Kochenov, ‘The Right to Have What Rights? EU Citizenship in Need of Clarification.’ (2013) 19 European Law Journal 502 p. 504, Reynolds (n 8) p. 388. f.
Case C-133/15, Chavez-Vilchez and Others, EU:C:2017:354, para 70.
Kochenov (n 90) p. 512 f.
Rendón Marín (n 12) paras 81–87, Case C-304/14, CS, EU:C:2016:674, para 20.
Opinion of Advocate General Szpunar in Case C-165/14, Rendón Marín, and Case C-304/14, CS, EU:C:2016:75, paras 130, 132.
Ibid., paras 125–126.
Ibid., paras 140–173.
See also, Katarina Hyltén-Cavallius, ‘Who Cares? Caregivers’ Derived Residence Rights from Children in EU Free Movement Law’ (2020) 57 Common Market Law Review 399.
Which may be reason to question the relevance of the substance of rights-doctrine, see van den Brink (n 57) p. 19.
Opinion in Rendón Marín and CS (n 94) paras 128–131.
For a clear stance against seeing the essence of EU fundamental rights as equal to the substance of Union citizenship rights, see Koen Lenaerts, ‘Limits on Limitations: The Essence of Fundamental Rights in the EU’ (2019) 20 German Law Journal 779 p. 783.
Rendón Marín (n 12) para 81.
Chavez-Vilchez (n 91) paras 66, 68–72. Compare to Iida (n 74), and Alokpa (n 12).
Chavez-Vilchez (n 91) para 63.
Ibid., paras 68–72.
Ibid., para 69.
Ibid., para 68. Whether these are cumulative conditions or stand-alone criteria, is not yet clear, see Neier (n 10) p. 565.
Rendón Marín (n 12) para 81, CS (n 93), paras 36 and 48.
Iida (n 74) paras 78–82, Dereci (n 74) paras 71–74.
Ciudad Real (n 63).
See van Eijken (n 73), Neier (n 10), Hester Kroeze, ‘The Substance of Rights: New Pieces of the Ruiz Zambrano Puzzle’ (2019) 44 European Law Review 238.
K.A. (n 80).
Ibid., para 97.
Ibid., paras 57–58. Compare to the Court’s reasoning the timing of family relationships in Case C-127/08, Metock and Others, EU:C:2008:449, paras 87–90.
K.A. (n 80) para 71, Chavez-Vilchez (n 91) para 68–70.
K.A. (n 80) para 65. Compare to McCarthy (n 74), Dereci (n 74).
Ciudad Real (n 63).
Ibid., para 61.
For a convincing argumentation on the concept of “empowering dependency”, see Delia Ferri and Giuseppe Martinico, ‘Revisiting the Ruiz Zambrano Doctrine and Exploring the Potential for Its Extensive Application’ (2021) 27 European Public Law 685.
Case C-221/17, Tjebbes and Others, EU:C:2019:189.
On the relationship between territory and Union citizenship, see Nic Shuibhne (n 62) p. 12.
Tjebbes (n 119) para 32.
Tjebbes (n 119) paras 44–45.
See the excellent analysis of the home Member State’s obligations by Strumia (n 5).
JY (n 46).
On the similarities between the protection under art. 21 and 20 TFEU, see van den Brink (n 57).
JY (n 46) paras 31–32, 39 and 47.
Ibid., para 39. See also Opinion in JY (n 58) paras 68–69.
JY (n 46) paras 39–47.
Ibid., paras 68–69.
Spaventa (n 3) p. 44. See Carpenter (n 64) and Zhu and Chen (n 20).
On the intertwining of primary law levelled residence and equal treatment rights with the fundamental status of Union citizenship, see Niamh Nic Shuibhne, ‘Derogating from the Free Movement of Persons: When Can EU Citizens Be Deported?’ (2006) 8 Cambridge Yearbook of European Legal Studies 187.
See Case C-424/10, Ziolkowski and Szeja, EU:C:2011:866, Case C-333/13, Dano, EU:C: 2014:2358 and Case C-67/14, Alimanovic, EU:C:2015:597 compared to Martínez Sala (n 19) and Trojani (n 29).
Compare Alimanovic (n 133) to Jobcenter Krefeld (n 39) and CG (n 20). See critique by Iliopoulou-Penot (n 2).
Compare the situation of the children in Ziolkowski (n 133) to those of the children in Case C-93/18, Bajratari, EU:C:2019:809, and again, to the children in Chavez-Vilchez (n 91). See critique by Adam Łazowski, ‘Children of a Lesser Law: Comment on Ziolkowski and Szeja’ (2013) 38 European Law Review 404.
Opinion of Advocate General Jacobs in Case C-168/91, Konstantinidis v Stadt Altensteig and Landratsamt Calw, EU:C:1992:504, para 46.
The string of cases: Rendón Marín (n 12), CS (n 93), Chavez-Vilchez (n 91), K.A. (n 80), Tjebbes (n 119), CG (n 20), and JY (n 46) all referred to the principle of proportionality, the protection of family and private life of art. 7 CFR, and the best interest of the child under art. 24(2) CFR, for a review of Member State measures that interferes with either art. 21 or art. 20 TFEU.
van den Brink (n 57) pp. 25–28.
As in Bajratari (n 135).
As it was in CG (n 20).
Compare the difference between the applicants in Chavez-Vilchez (n 91) depending on whether they relied on Art. 21 TFEU and Directive 2004/38, or Art. 20 TFEU. Neier (n 10) p. 550.
CG (n 20).
Case C-182/15, Petruhhin, EU:C:2016:630, Case C-398/19, Generalstaatsanwaltschaft Berlin (Extradition to Ukraine) (BY), EU:C:2020:1032.
Petruhhin (n 143). See also Case C-191/16, Pisciotti, EU:C:2018:222.
Martin Böse, ‘Mutual Recognition, Extradition to Third Countries and Union Citizenship: Petruhhin’ (2017) 54 Common Market Law Review 1781 p. 1787. Those who have made use of freedom of movement are more likely to be protected by Art. 21 TFEU than Art. 20 TFEU, see analysis by Nic Shuibhne (n 62) pp. 32–37.
On the divergence in proportionality assessments under art. 21 and art. 20 TFEU, See van den Brink (n 6) p. 95.
Bajratari (n 135) See Opinion in Bajratari (n 14) para 86. The judgment in Jobcenter Krefeld (n 39) does not remedy this dissonance between art. 21 TFEU and art. 20 TFEU. See however CG (n 20).
Chavez-Vilchez (n 91) paras 70–72, K.A. (n 80) para 71. On this point, see van Eijken (n 73) p. 66.
This was also the case regarding the child exercising freedom of movement in Rendón Marín (n 12).
CG (n 20) paras 87–92.
van den Brink (n 57) p. 26 and Lenaerts (n 100) p. 783.
Eleanor Spaventa, ‘Earned Citizenship: Understanding Union Citizenship Through Its Scope’ in Dimitry Kochenov (ed), EU Citizenship and Federalism: The Role of Rights (Cambridge University Press 2017) pp. 220–221.
See Neier (n 10).
As noted also by Fulvia Staiano, ‘Derivative Residence Rights for Parents of Union Citizen Children under Article 20 TFEU: Chavez-Vilchez’ (2018) 55 Common Market Law Review 225 p. 231. See also Jobcenter Krefeld (n 39).
Compare to Martínez Sala (n 19).
CG (n 20) paras 84–91.
See Ziolkowski (n 133), Alokpa (n 12), Bajratari (n 135).
Ciudad Real (n 63) paras 47–49.
Neier (n 10) p. 559.
Chiara Raucea, ‘European Citizenship and the Right to Reside: “No One on the Outside Has a Right to Be Inside?”’ (2016) 22 European Law Journal 470 p. 477.
See Opinion in Konstantinidis (n 136). See analysis by Daniel Sarmiento and Eleanor Sharpston, ‘European Citizenship and Its New Union: Time to Move On?’ in Dimitry Kochenov (ed), EU Citizenship and Federalism: The Role of Rights (Cambridge University Press 2017).
Questioning the appropriateness of the ‘primary caregiver’-concept and dependency-test, is Staiano (n 155) p. 233 and p. 238 f.
A persistent problem that arose already at the time of the Ruiz Zambrano judgment, see Hailbronner and Thym (n 8) p. 1269.
What Nic Shuibhne refers to as a ‘protective’ narrative, to keep the Union citizen within the territorial space of the Union, Nic Shuibhne (n 62) p. 19, and p. 26 f.
Although this allocation of responsibility may be modified in some cases, see Rendón Marín (n 12) para 79.