Introduction

This chapter covers some of the most fiercely contested territory of EU law. Sovereignty and federalism are as politically sensitive as they are legally central to the European project. Both terms – sovereignty and federalism – are subjects on which there is vast literature in legal theory and political science. The definitions and implications of the terms are examined from dozens of angles and at exhaustive length. The good news is that we are not especially concerned with sovereignty or federalism as general concepts in politico-legal studies. We are not seeking a mastery of the myriad meanings these terms may be said to possess. Rather, we are concerned simply with the doctrine and practice of sovereignty and federalism as principles of EU law. As such, in the present context, sovereignty concerns the authority enjoyed by EU law over the law, including the constitutional law, of the Member States. In this chapter we explore, first, the claim that the European Court of Justice has made for the sovereignty of European law. Then we turn to consider the reaction of the Member States. Federalism concerns the constitutional relationship between the central authorities and the constituent parts of the European Union. In this chapter we focus, in particular, on the relationship as it is manifested in the allocation of law-making powers between the institutions on the one hand and the Member States on the other.