At the European level, the principle of non-discrimination is expressly stated first and foremost in Article 2 of the TEU. In the context of the EEC, this principle exclusively reflected the rejection of any protectionist policy that might hinder, not only the creation of the common market, but more broadly the realization of any form of free trade. With the transition to the EU and, above all, the institution of European citizenship, on the other hand, the prohibition of non-discrimination becomes part of this restricted group of principles that characterize the profound purpose of the new European project – that is, the assimilation of the citizens of the member states – becoming an instrument for the affirmation of the EU as a unitary space based on identity. The research that is conducted concerns the Principle of non-discrimination within the European Union and the attribution of horizontal direct effects in the jurisprudence of the Court of Justice of the European Union.
