Equality Among Member States and Differentiated Integration in the EU

Abstract

This chapter examines the relationship between the principle of equality among Member States and the differentiation mechanisms used in the European Union’s integration process. It aims at evaluating the impact of the principle on the possibilities for differentiation at the level of primary EU law—such as the Economic and Monetary Union and Schengen—and secondary EU law. The first part analyses the many faces of the equality principle and its constitutionalization in EU law. The chapter proceeds with an examination of differentiation at the level of primary and secondary EU law and within Member States, and the impact of the equality principle as interpreted in the case-law of the Court of Justice. It appears that the impact of the principle on differentiation mechanisms is multifaceted and complex, presenting ‘multi-layers’ and ‘multi-players’ features.