The doctrine of supremacy is essential to the uniformity of the EU legal edifice. It had no formal basis in the Treaty Law but was developed by the Court of Justice of the EU by means of its conception of the “new legal order” (Costa v ENEL). Therefore, the corollary of sovereignty of the EU legal order is the supremacy of EU law: any norm of EU law takes precedence over any provision of national law. From the CJEU’s perspective, supremacy entails duty for the national courts to ‘set aside’ any conflicting national norm when an EU rule applies in a given case. Ultimately, the acceptance and application of the supremacy of EU law are dependent on the Member States. Despite its invention, acceptance of the doctrine of supremacy has been the main challenge within the overall integration process. Recent ruling from the German Constitutional Court (the Bundesverfassungsgericht) on the legality of the European Central Bank’s Programme marked that the supremacy issue cannot be put ‘ad acta’ and still continues to be surrounded with ambiguity and controversy against its unconditional acceptance as the CJEU requires. This paper summarizes the most remarkable aspects of the foundations of the supremacy doctrine and the conceptual basis on which the Member States accord supremacy to EU law, as well as its scope and limits. All this is necessary in order to be able to determine the perspectives for ensuring the supremacy of EU law, while highlighting its importance for the future of the European integration.

Keywords: EU legal order, doctrine of supremacy, sovereignty, CJEU, national courts.