This article considers recent legal developments on undocumented migrant workers, finds the acceptance of international legal standards unsatisfactory and argues that the private law rights derived from the “semi-legal” employment contract between the employer and the undocumented migrant worker generates a solid base for significant legal claims. It further monitors the promotion of the position of the undocumented migrant workers under recent EU law and calls for a refocusing on the employment contract in the reading of a relevant EC Directive, with a particular emphasis on the issue of access to justice for the migrant workers. The increased number of undocumented migrants who leave their countries of origin for reasons outside the scope of the asylum procedure, as well as the circumstances under which this migration is undertaken and the working conditions of these individuals in the host countries, have brought about legal activities from governments and institutions such as the EU. The aim has in general been to establish sanctions against employers of undocumented migrant workers, but a shift towards a compensatory, employee protective, attitude has recently emerged, both in EU legislation and in a broader perspective in US case law. The article concludes that such a development must be massively supported in relation to access to justice in order to fulfill the ambition. The poor legal position of the undocumented migrant workers is significantly connected to issues of legal representation, trade union participation and the threat of repatriation.