Since its creation in 2010, the Priority Question of Constitutionality has represented a major revolution in the French legal system. This mechanism enables litigants to challenge the constitutionality of a law directly applicable to their dispute, transforming the relationship between citizens and the constitutional norm. For legal professionals, mastering the QPC is becoming essential in the context of French institutions and regulations.

What is QPC?

The Question Prioritaire de Constitutionnalité (QPC) is a mechanism that enables any citizen involved in legal proceedings to challenge a law that he or she considers contrary to the Constitution. Unlike checks carried out before laws are published, the QPC intervenes a posteriori, i.e. after they have come into force, when the law poses a problem in a specific case.

An emblematic example perfectly illustrates this mechanism: in 2010, the QPC on police custody led to a profound reform of this criminal procedure, reinforcing the rights of the defense. Unlike a priori control exercised before laws are enacted, the QPC comes into play when citizens are directly affected by a potentially unconstitutional law. This procedure is designed to protect the constitutional rights and freedoms guaranteed by the Constitution.

Since 2010, over 5,000 QPCs have been raised in French courts, of which around 15% have been referred to the Conseil constitutionnel. The mechanism is based on three fundamental criteria: the disputed provision must be applicable to the dispute, it must not have already been declared to be in conformity with the Constitution, and the question must be of a serious nature.

QPC conditions and procedure

The QPC procedure is based on a system of successive double review: first by the court hearing the case, then by the supreme courts. This mechanism guarantees rigorous filtering before transmission to the Constitutional Council.

First stage – Initial screening: The lower court examines three conditions of admissibility: the applicability of the provision to the current dispute, the absence of a previous declaration of conformity by the Conseil constitutionnel, and the serious nature of the question raised. It has a mandatory period of three months in which to rule, failing which the question is deemed to have been transmitted.

Second stage – Filtering by the supreme courts: In the event of a referral, the Cour de cassation or the Conseil d’État carry out a second review. These courts verify the same criteria, while ensuring that the question has a new dimension or is of particular importance. The rate of referrals by the lower courts is around 15%, demonstrating the selectivity of the process.

The supreme courts also have three months in which to refer a case to the Conseil constitutionnel, and the average time taken to process a QPC is 4 to 6 months from the time it is first raised. To find out more about these procedural aspects, read our articles on QPC.

The role of the Conseil constitutionnel in QPC proceedings

The Conseil constitutionnel has three months to issue its decision on the QPC submitted. This institution examines the conformity of the legislative provision with the rights and freedoms guaranteed by the Constitution, drawing on the bloc de constitutionnalité which includes the 1958 Constitution, the 1946 Preamble and the 1789 Declaration of the Rights of Man and of the Citizen.

The Council’s decisions can take several forms: declaration of conformity (maintaining the provision in force), declaration of unconstitutionality with immediate repeal, or declaration of unconstitutionality with deferred repeal. The latter accounts for around 40% of decisions of unconstitutionality, enabling a controlled legal transition.

Deferred repeal allows the legislator to amend the provision within a given timeframe, thus avoiding a legal vacuum. This modality illustrates the search for a balance between the protection of fundamental rights and legal certainty. A striking example is the 2010 ruling on police custody, which led to a major reform of criminal procedure with a deferral period of several months.

Since 2010, the Conseil constitutionnel has handed down more than 1,000 QPC decisions, with an annual average of between 80 and 90. Of these decisions, around 35% have resulted in a declaration of unconstitutionality, in whole or in part, demonstrating the effectiveness of this mechanism in the evolution and purification of French law.

Impact of QPC on legal practice

The QPC is profoundly transforming lawyers’ litigation strategy. It offers a new defense tool for directly challenging the legal basis of a procedure or sanction, revolutionizing the traditional approach to litigation.

Practitioners must now integrate constitutional analysis into their day-to-day legal thinking. This development calls for appropriate continuing education, accessible in particular through online lawyer training. Since 2010, the range of training courses on offer has expanded considerably, with the emergence of specialized modules in applied constitutional law.

Certain areas of law are particularly affected by QPC. Criminal law, tax law, labor law and family law account for the majority of questions submitted. In criminal law in particular, the QPC has made it possible to call into question numerous provisions relating to investigation procedures and sanctions.

The statistical impact remains significant: according to data available from the Conseil constitutionnel, around a third of QPCs submitted result in a declaration of total or partial unconstitutionality, although this rate varies according to the period and legal field concerned. This proportion encourages practitioners to explore this avenue when the conditions are right.

QPC also influences the drafting of documents and the conduct of proceedings. Lawyers need to anticipate potential constitutional arguments right from the advice phase, adapt their arguments accordingly and develop an active constitutional case law watch to identify opportunities for challenge.

QPC and the evolution of French constitutional law

The Question Prioritaire de Constitutionnalité has profoundly renewed French constitutional law. It has enabled the emergence of a living constitutional law, in direct contact with the concerns of those subject to the law.

This procedure has strengthened the effectiveness of fundamental rights by enabling them to be invoked directly before the ordinary courts. It thus contributes to the spread of constitutional culture throughout the legal system.

The jurisprudential evolution generated by the QPC is constantly enriching the corpus of constitutional rights and freedoms. The Constitutional Council regularly clarifies the scope of constitutional principles in its decisions.

This dynamic is part of a wider process of modernizing legal regulation and training, which requires ongoing adaptation by legal professionals.

The QPC is thus an essential tool for protecting fundamental rights and modernizing the French legal system. Mastering it is a major challenge for all those involved in contemporary law.