How to enforce European law? A new history of the battle over the direct effect of Directives, 1958–1987

This article explores the well‐known saga of the European Court of Justice's introduction of direct effect of Council Directives on the basis of new comprehensive archival research. The expansion of the doctrine of direct effect to include Directives was part of a drive of the Legal Service of the European Commission and the ECJ to strengthen the enforcement of European law. This threatened the deeper balance of competences between the European Community and its Member States and consequently led to a sharp response from the national parliaments and courts. The force of these responses and the deep crisis that had evolved in the late 1970s between France and the ECJ, led to a change in the EC's case law that limited the direct effect of Directives to the vertical relation between citizens and the respective Member State and excluded any horizontal effect. The story is an example of how the activist ECJ of the 1970s ran into resistance from the Member States and had to modify its doctrinal advances. It also suggests that the successful acceptance of the constitutionalisation of the Treaties of Rome pursued by the ECJ was by no means secure by the late 1970s.