The promotion and protection of social rights within the legal order of the European Union was always considered with suspicion, not only because of the doubts concerning the status of such rights -- and in particular concerning their justiciability --, but also because of the potential impacts of the recognition of social rights at EU level on the allocation of competences between the EU and its Member States, and because of the original understanding of European integration in the 1957 Treaty of Rome establishing the European Economic Community, which to a large extent was premised on the decoupling between the economic and the social spheres in the European project. This paper examines the impacts on this debate of the proclamation in 2000 of the Charter of Fundamental Rights, and of the later incorporation of the Charter in the European Treaties. The Charter recognizes social rights as part of the fundamental rights acquis of the Union. But the status of social rights in the Charter also reflects the fears that have always imposed limitations to such recognition. In order to illustrate how, this paper replaces the social provisions of the Charter of Fundamental Rights within the broader context of social provisions in the constitutional architecture of the EU, in order to assess its added value. It first recalls the conditions under which the Charter of Fundamental Rights was drafted, and how the social provisions of the Charter were inspired by theexisting acquis of social rights, both in EU law and in regional or international human rights instruments (2). Next, it assesses the impact of the Charter on the working methods of the European Commission and the Council of the EU (3). It then turns to the implications of the constitutionalization of the Charter by the Treaty of Lisbon (4). It examines in this regard a number of questions that are crucial to assess the contribution of the Charter to Social Europe: they include the distinction between 'rights' and 'principles' presupposed in the amended version of the Charter; the positive duties that may be imposed on the basis of the Charter; or the role of the Charter in influencing the exercise by the institutions of the EU of the competences they have been attributed. A brief conclusion is offered .