6 United Nations Convention Against Torture and its Optional Protocol reports to States parties with far-​reaching recommendations have had a significant impact on improving conditions of detention and the treatment of detainees in most of the member States of the Council of Europe.29 After the end of the Cold War, the UN Commission on Human Rights took up the idea of Jean-​Jacques Gautier and entrusted another inter-​sessional Working Group with the task of drafting an Optional Protocol to the CAT. The Working Group based its deliberations on a revised draft submitted by Costa Rica and was chaired by Elizabeth Odio Benito, former Minister of Justice of Costa Rica.30 The highly controversial and political discussions between European and most Latin American States on the one hand, and a broad variety of other States on the other, concerning primarily issues of State sovereignty, blocked any significant progress during the 1990s. Only after Mexico had reacted on the European States’ suggestion of a very strong SPT with a far-​reaching mandate and introduced the idea of establishing domestic visiting commissions (so-​called national preventive mechanisms)31 in addition to the international monitoring body (the UN Subcommittee on Prevention of Torture [SPT]),32 could a broad majority be formed to adopt the OP by majority vote. The OP was adopted on 18 December 2002 in the General Assembly by a vote of 127 States in favour, four against and forty-​two abstentions.33 On 22 June 2006, ie thirty days after the date of deposit of the twentieth instrument of ratification, the OP entered into force.34 On 18 December 2006, the States parties to the OP elected the first ten independent experts of the SPT,35 which held its first session in Geneva from 19 to 23 February 2007.36 As of 31 December 2017, a total of 84 States parties to CAT had ratified or acceded to the OP.37 3.  Content and Significance of the Convention and Protocol The Convention against Torture was adopted in 1984 as a specialized human rights treaty in response to the widespread and systematic practice of torture in Latin America and other regions of the world. Since the prohibition of torture and cruel, inhuman or degrading treatment or punishment has been recognized in Article 7 CCPR and other international and regional human rights treaties as an absolute and non-​derogable human right and is also considered as jus cogens, the drafters of the Convention abstained from reiterating this principle. Rather, the Convention is based on the explicit desire of its drafters ‘to make more effective the struggle against torture and other cruel, inhuman or 29   cf eg Malcolm D Evans and Rodney Morgan, Preventing Torture: A Study of the European Convention for the Prevention of Torture and Inhuman or Degrading Treatment or Punishment (Clarendon Press/​OUP 1998); Malcolm D Evans and Rodney Morgan (eds), Protecting Prisoners: The Standards of the European Committee for the Prevention of Torture (Oxford University Press 1999); Ursula Kriebaum, Folterprävention in Europa: Die Europäische Konvention zur Verhütung von Folter und unmenschlicher oder erniedrigender Behandlung oder Bestrafung (Verlag Österreich, 2000). 30 31   For the drafting history of the OP see below Preamble OP.   See below Arts 17 to 23 OP. 32   See below Arts 5 to 16 OP. 33   GA Res 57/​199 of 18 December 2002; see below Preamble OP; Art 27 OP, § 17; see also APT, ‘Position Paper on the Optional Protocol to the UN Convention against Torture: Added Value of the Optional Protocol for States Parties to the European Convention for the Prevention of Torture’ (2003); APT and IIDH, Optional Protocol to the UN Convention Against Torture: Implementation Manual (rev edn, APT and IIDH 2010). 34 35   See below Art 28 OP.   See below Art 7 OP; as well as Appendix B5. 36 37   See below Art 10 OP.   See below Art 27 OP; as well as Appendix B3.