The general principles of European Law and French administrative case law

The general principles of EU law, which are a judicial creation of the Court of Justice, play a role in French administrative case law that can be explained by the notion of functional duplication (dédoublement fonctionnel). On the one hand, the general principles of EU law are rules that are mandatorily applied by the national courts within the scope of EU law. On the other hand, beyond that scope, they constitute a source of inspiration for the Conseil d'Etat in creating and interpreting general principles of French administrative law. In the first case, the administrative courts are the prime guarantors of compliance with these principles. In line with the requirements of the Court of Justice, they entirely fulfill their role as the ordinary courts applying principles of EU law. In the second case, they become one of the protagonists of the movement of principles in Europe. However, the coexistence of principles could trigger tensions, heightened by the difficulties in delineating the scope of principles of EU law, which is uncertain and rapidly expanding. That is why the thesis proposes the development of a judicialconvergence policy, in which the administrative courts would more clearly affirm their concern to take inspiration from the general principles of EU law.  These latter, combined with the principles stemming from the Charter of Fundamental Rights, the ECHR and the national orders, seem to give rise to a new category of material source: the common European principles. The originality of this category, which differentiates it from any other source, is that it constitutes a collective work of judges in Europe, from which they draw their inspiration to create new principles or interpret the existing ones.