The competence of the European Union in the field of labour law is limited to the support, complementation and coordination of the activities of the Member States in the exhaustive areas of labour law. The diversity of national definition of legal concepts used in EU challenges the harmonisation of national legal orders and their gradual convergence. The lack of consistency between Member States in respect of determination of who qualifies as a “worker” in national legal orders lead to the differences between Member States, as regards the application of the minimum standards to the same category of persons performing a paid job. This can undermine the objectives pursued by directives and may jeopardise their effectiveness. A uniform concept of “worker” has not yet been developed at the EU level. The starting point for any discussion about the concept of “worker” in EU law is the definition of “worker” provided for the principle of free movement of workers enshrined in Art. 45 of TFEU. Given the non-discriminatory purpose of the concept of worker under the principle of free movement of workers, this article is going to consider whether this concept has the potential for broader protection of workers in the EU.