The Constitutional Council (Conseil Constitutionnel) is the highest constitutional authority in France. It was established by the Constitution of the Fifth Republic on 4 October 1958, and its duty is to ensure that the principles and rules of the constitution are upheld.
Its main activity is to rule on whether proposed statutes conform with the Constitution, after they have been voted by Parliament and before they are signed into law by the President of the Republic (a priori review); since 1 March 2010, individual citizens party to a trial or lawsuit can also ask for the Council to review whether the law applied in the case is constitutional. In 1971, the Council ruled that conformity with the Constitution entails conformity with two texts referred to by the preamble of that constitution: the Declaration of the Rights of Man and of the Citizen and the preamble of the constitution of the Fourth Republic, both of which list constitutional rights (e.g. freedom of speech).