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), or passed by the government as a decree, which has law status in many domains, a right granted to the government under delegation of Parliament.

[1][2] Members are referred to as les sages ("the wise") in the media and the general public, as well as in the council's own documents.

Guidance may be sought from the council in regard to whether reform should come under statute law (voted by Parliament) or whether issues are considered as règlement (regulation) to be adopted with decree of the prime minister.

The re-definition of legislative dispositions as regulatory matters initially constituted a significant share of the (then light) caseload of the council.

[8] Another task, of lesser importance in terms of number of referrals, is the reclassification of statute law into the domain of regulations on the prime minister's request.

Any citizen with an interest in the case can obtain the cancellation of these regulations by the Council of State, on grounds that the executive has exceeded its authority.

[15] In addition, new acts can be referred to the Constitutional Council by a petition just prior to being signed into law by the president of the republic.

This reluctance was based in the French revolutionary era: pre-revolutionary courts had often used their power to refuse to register laws and thus prevent their application for political purposes, and had blocked reforms.

A 2009 reform, effective on 1 March 2010, enables parties to a lawsuit or trial to question the constitutionality of the law that is being applied to them.

[10][11][12] Originally, the council was meant to have rather technical responsibilities: ensuring that national elections were fair, arbitrating the division between statute law (from the legislative) and regulation (from the executive), etc.

[20] In 1971, however, the Council ruled unconstitutional (Decision 71-44DC) some provisions of a law changing the rules for the incorporation of private nonprofit associations, because they infringed on freedom of association, one of the principles of the 1789 Declaration of the Rights of Man and of the Citizen; they used the fact that the preamble of the French constitution briefly referred to those principles to justify their decision.

[28][31] The practice of the Parliament putting into laws remarks or wishes with no clear legal consequences has been a long-standing concern of French jurists.

This controversial decision is now moot, since the Parliament redefined the rules of responsibility of the president of the republic by the French constitutional law of 23 July 2008.

[38] In 1999, because of the Elf scandal, Dumas took official leave from the Council and Yves Guéna assumed the interim presidency.

[39] In 2005, the council again attracted some controversy when Valéry Giscard d'Estaing and Simone Veil campaigned for the proposed European Constitution, which was submitted to the French voters in a referendum.

This action was criticized by some, including Jean-Louis Debré, president of the National Assembly, who thought that prohibitions against appointed members of the council conducting partisan politics should not be evaded by their taking leave for the duration of a campaign.

Following the 2008 constitutional revision, appointments that the president of the republic makes to the council are subject to a parliamentary approval process, where the relevant committee in the Senate and the National Assembly votes on the appointee.

The possibility for former presidents to sit in the council is a topic of moderate controversy; some see it as incompatible with the absence of partisanship.

[41] René Coty, Vincent Auriol, Valéry Giscard d'Estaing, Jacques Chirac and Nicolas Sarkozy are the only former Presidents of France to have sat in the Constitutional Council.

Decisions of the council traditionally include an extremely short and purely formal judicial opinion, often relying of plain statements if not tautologies, leaving its rationale and its use of principles and precedents open to interpretation.

Before 1996, secretaries general occasionally contributed articles in law reviews in order to clarify the council's intents.

The purpose of the Cahiers, as summed up by its then-editor, was also to "express the policy of dialogue of the Constitutional Council with academia as well as with foreign courts".

[50] Each issue included a special feature, as well as an article on a foreign constitutional court, authored by legal scholars and researchers.