The impact, effect and influence of Community law on domestic law is dependent on the principle of supremacy of the former over the latter. The concept of supremacy of EC law is directly related to the principle of direct effect, direct applicability and self-execution. The first is pertinent to implementation while the others are to enforcement. It would certainly be impossible to achieve the objective of the Community if its laws cannot be implemented consistently among its members.
In traditional international law, the determination of whether a certain provision is directly effective is decided by domestic law. It is also domestic law that will determine what are the conditions under which such effectiveness applies. This traditional mechanism was short-circuited by the European Community due its supra-national status and evolved the Community into a legal order sui generis.
The principle of supremacy is implied in the very creation of the Community, this is the gist of several decisions of the European court justifying compliance with Community law. Its articulation was necessary for the enforcement of Community law through national authorities and courts.1 The determination of supremacy, direct effectiveness, direct applicability and self-execution of the provisions of Community law is done under the procedures and precepts of Community law.
These doctrines are actually described as constitutionalizing; implementing supra-national effect of the treaty in its member states. As stated in Les Verts2, "The EEC is a Community based on the rule of law, inasmuch as neither its Member States not its institutions can avoid a review of the question whether the measures adopted by them are in conformity with the basic constitutional charter, the Treaty."
These same doctrines also point to an umbrella principle, which their operation imply - that of supremacy of EC law over national law. Indeed, in case of conflict, Community law overrules national law in order for Community law to be effective and for the same purpose, the European Court of Justice is given the final pronouncement with regard to Community law. In the words of Costa v ENEL3:
By contrast with ordinary international treaties, the EEC Treaty has created its own legal system which, on the entry into force of the Treaty, became an integral part of the legal systems of the Member States and which their courts are bound to apply.
By creating a Community of unlimited duration, having its own institutions, its own personality its own legal capacity and capacity of representation on the international plane and, more particularly, real powers stemming from a limitation of sovereignty or a transfer of powers from the states to the Community, the Member States have limited their sovereign rights, albeit within limited fields, and have thus created a body of law which binds both their nationals and themselves.
The integration into the laws of each Member State of provisions which derive from the Community, and more generally the terms and spirit of the Treaty, make it impossible for the states, as a corollary, to accord precedence to a unilateral and subsequent measure over a legal system accepted by them on a basis of