Is there a sovereignty problem in the EU?

In the process of the European integration, the role of the state seems again to have become stronger over the last fifteen years: oppositions against treaty reforms were carried by national public opinions, framed by state borders; decisions with regard to rescue packages were decided on the basis of governmental debates and included much less than in the past supranational institutions. This contribution aims at analysing the challenges state sovereignty - newly affirmed and old - poses to theoretical approaches of European integration. It does so in two parts. It discusses the question of sovereignty in the regional integration schemes more generally in a first part. In distinguishing between internal and external state sovereignty, my aim is to consider sovereignty not so much as a juridical concept than as a concept whose importance varies according to perception and construction by social agents. A second part will then develop a conceptual framework based on the usage of sovereignty by members state officials both at the EU and the national level