Article 24

Notwithstanding the provisions of Article 15, any State may, when signing this Convention or depositing its instrument of ratification, acceptance or accession, or at any later date, by notification addressed to the Secretary General of the Council of Europe, declare that, in cases not falling within Articles 1 to 13, its courts shall be entitled to entertain proceedings against another Contracting State to the extent that its courts are entitled to entertain proceedings against States not Party to the present Convention. Such a declaration shall be without prejudice to the immunity from jurisdiction which foreign States enjoy in respect of acts performed in the exercise of sovereign authority (acta jure imperii).

The courts of a State which has made the declaration provided for in paragraph 1 shall not however be entitled to entertain such proceedings against another Contracting State if their jurisdiction could have been based solely on one or more of the grounds mentioned in the Annex to the present Convention, unless that other Contracting State has taken a step in the proceedings relating to the merits without first challenging the jurisdiction of the court.

The provisions of Chapter II apply to proceedings instituted against a Contracting State in accordance with the present Article.

The declaration made under paragraph 1 may be withdrawn by notification addressed to the Secretary General of the Council of Europe. The withdrawal shall take effect three months after the date of its receipt, but this shall not affect proceedings instituted before the date on which the withdrawal becomes effective.