The Plenary of the Court shall examine the constitutionality, in respect of both form and substance, of laws, decrees having the force of law and the Rules of Procedure of the Grand National Assembly of Turkey. Constitutional amendments shall be examined and verified only with regard to their form.
However, decrees having the force of law issued during a state of emergency, martial law or in time of war shall not be brought before the Constitutional Court alleging their unconstitutionality as to form or substance. In addition, no appeal to the Constitutional Court shall be made with regard to international agreements, on the grounds that they are unconstitutional.
There are two procedures for constitutionality review. One of them is Action for Annulment and the other is Contention of Unconstitutionality. While the Action for Annulment is also known as abstract control of norms the Contention of Unconstitutionality is named as concrete control of norms. Because contention of unconstitutionality can be initiated by general administrative and military courts and any party involved in a case being under scrutiny before a court.
The President of the Republic, parliamentary groups of the party in power and of the main opposition party and a minimum of one-fifth of the total number of members of the Turkish Grand National Assembly have the right to apply for annulment action to the Constitutional Court. If more than one political party is in power, the party having the greatest number of members exercises the right of the parties in power to apply for annulment action.
As a rule, the right to apply for annulment directly to the Constitutional Court lapses sixty days after publication in the Official Gazette of the relevant legislation. However, applications for annulment on the grounds of defect in form shall not be made after ten days have elapsed from the date of promulgation of the law.
Verification as to form may be requested by the President of the Republic or by one-fifth of the members of the Grand National Assembly of Turkey.
Being different from the abstract control of norms, contention of unconstitutionality can be initiated only against laws and decrees having the force of law. And it shall not be appealed by other courts to the Constitutional Court on the grounds of defect in form.
In this procedure, if a court finds a quo that the law or the decree having the force of law to be applied is unconstitutional, or if it is convinced of the seriousness of a claim of unconstitutionality submitted by one of the parties, it postpones the consideration of the case until the Constitutional Court decides on the issue. The Constitutional Court shall decide on the matter within five months of receiving the contention. If no decision is reached within this period, the trial court concludes the case under existing legal provisions. No allegation of unconstitutionality shall be made with regard to the same legal provision until ten years elapse after publication in the Official Gazette of the decision of the Constitutional Court dismissing the application on its merits.