Assuming that supremacy outlines the relationship between the member state and the EU, by the same criteria Direct Effect defines the relationship between the citizen of the various member states and the EU in the forms of its laws. Therefore, Direct Effect is one of the major element in ensuring that the EU law is applied harmoniously through the member States. Direct effect demonstrates the supranational nature of EU law by ensuring that a citizen is able to enforce it in member state courts. It was established by the European Court Of justice.
The concept of Direct Effect is not mentioned anywhere in the treaties, but is entirely established by the European Court of Justice (ECJ). Direct Effect refers to the actual enforceability of EU law, in any form, in the national courts of member states. Where the law creates actual right and obligations then the concept can be applied to treaty articles and to regulation and even to decision. Moreover, Direct Effect is the major instrument in ensuring that the objective of the treaties is observed by the member state and incorporated into national law. ‘Direct effect is the first step in the judicial contribution to federalism’1. The Lisbon treaty never properly distinguished that who can or cannot use Direct Effect, due to which the doctrine in the case of Van Gen den Loos2 was established, where the criteria was based on two provisions. Firstly, that the provision must be ‘sufficient clear’ and ‘precisely stated’, where in the case of Defrenne v Sabena3 the ECJ was satisfied with the principle of men and women receiving equal pay for equal work was sufficiently precise to create direct effect. Secondly, that the provision must be unconditional or non-dependent, which means that it should not be dependent on intervention of another body nor require further legislative action either by the community intuitions or member states.
1 P Craig, ‘once upon a time in the west: direct effect and the federalization of EC law’ 1992 OJLS 453
2 1963 ECR 1
3 1975 ECR 455