Protocol shall form an integral part of this Treaty. The provisions of that Act shall form an integral part of this Treaty. This Treaty shall be ratified by the High Contracting Parties in accordance with their respective constitutional requirements. The instruments of ratification shall be deposited with the Government of the Italian Republic by 31 December 2006 at the latest. This Treaty shall enter into force on 1 January 2007 provided that all the instruments of ratification have been deposited before that date. If such a decision is taken with respect to only one of the acceding States this Treaty shall enter into force for that State on 1 January 2008. These measures shall enter into force only subject to and on the date of the entry into