Conflicts and Integration - Revisiting Costa v ENEL and Simmental II

This short chapter revisits the cases Costa v ENEL and Simmenthal II and their effect on the development of the specific nature and the constitutional order of the EU. Costa v ENEL and Simmenthal II are cases well known for their impact on defining the legal parameters which govern the legal system of the EU/EC. These cases are true classics in the history of case law of the ECJ and thus have been discussed to great detail in legal writing. I will not attempt within this chapter to do justice to the nuances and the ongoing debates in this literature. Instead, this chapter will focus on a more rarely addressed but nonetheless central aspect of the cases: It will argue that the specific contribution of Costa v ENEL and Simmenthal II to the development and definition of the Community legal system, arises from a fruitful and productive tension. This tension results from a dichotomy between, on one hand, a rule of conflicts, and, on the other, the notion of the integration of legal systems. Initially, the principle of supremacy, as outlined in these cases, seems to be establishing a hierarchy of norms between EC and national law. It introduces a conflicts rule giving precedence to Community law over national legal provisions in cases of conflict. The cases however equally establish the notion of integration, which, according to Costa v ENEL and Simmenthal II, is based on the E(E)C Treaty having ‘created its own legal system’ which upon entry into force ‘became an integral part of the legal systems of the Member States’ and is ‘applicable in the territory of each of the Member States.’ The establishment of the principle of supremacy therefore has not led simply to the superimposition of a new level of public power over that of the Member States. The ECJ’s approach in its case law from Costa v ENEL to Simmenthal II led to a unique system of shared sovereignty, in which hierarchic relations are only elements within a wider structure of jointly exercising public powers. The chapter is committed to exploring this unique method of sharing sovereignty within the tension between conflicts and integration.