The manifestation of religion is protected in the United Kingdom by human rights instruments and also, since 2003, by discrimination law. When religious faith is manifested in the workplace it potentially involves some clash with other rights, particularly an employer's freedom of contract. How far an employer is able to restrict its employees' freedom to manifest religion in pursuit of a 'legitimate aim' is therefore of great interest to employers and 'religious' employees alike. This article explores this issue by first categorising 'manifestation' into three forms and then surveying the jurisprudence relevant to each, considering most recent cases in greater detail. Although it is acknowledged that conclusions must be tentative, given the relatively recent innovation of the discrimination law provisions, evidence considered in this article points towards very little protection for employees to manifest their religious convictions except those aspects of what is referred to here as 'negative manifestation' which are most congruent with the private sphere—the so-called forum internum.