[JURIST] The All Party Parliamentary Group on Extraordinary Rendition (APPG) [official website] released a legal opinion [text, PDF] on Monday which examines UK governmental liability under the European Convention on Human Rights (ECHR) [text, PDF] and the UK Human Rights Act 1998 (HRA) [text] for its participation in the CIA extraordinary rendition [JURIST news archive] program. The opinion states that a human rights violation under both the ECHR and the HRA would occur where "an individual in British detention in Iraq is handed over to US military personnel despite substantial grounds for considering that there is a real risk of that person being subjected to torture or inhuman and degrading treatment." The opinion also determined that US assurances that suspects handed over by the UK would not be tortured would not be sufficient to absolve the UK of its obligations under the ECHR and the HRA:

The United States Government has registered reservations to the International Covenant on Civil and Political Rights and the Convention Against Torture stipulating that it considers itself bound by the prohibition of cruel, inhuman and degrading treatment only to the extent that it is prohibited by the Fifth, Eighth and/or Fourteenth Amendments to the US Constitution and, moreover, the reservation also sets out a definition of torture that is narrower than that accepted by courts in the United Kingdom (in particular, in referring to an act intended to inflict severe physical pain and suffering). An undertaking not to engage in inhuman and degrading treatment or torture would not therefore necessarily be sufficient to discharge the United Kingdom’s obligations under the ECHR. … The US military, which would be responsible for the detention of detainees handed-over by the British military authorities, are known to have applied “enhanced interrogation techniques” to those within their custody believed to have intelligence value. These techniques are capable of amounting to inhuman and degrading treatment and torture in domestic law. In A (No. 2), Lord Hope, in considering what conduct is capable of amounting to torture, stated that some of the interrogation techniques authorized for use in Guantanamo Bay, “would shock the conscience if they were ever to be authorized for use in our own country” (A (No.2) v Secretary of State for the Home Department […]. Lord Bingham stated that the interrogation techniques used by British authorities in Northern Ireland during the troubles, which were categorized as “inhuman and degrading” by the ECtHR in Ireland v United Kingdom (1978) 2 EHRR 25, would today be regarded as torture […]

The Guardian has more.

The APPG was convened in December 2005 [JURIST report] to call for a formal inquiry into whether the British government violated international law by aiding the CIA rendition flights. In July, the UK House of Commons Foreign Affairs Committee called "deplorable" [JURIST report] what it termed "false US assurances" about extraordinary rendition flights through the UK Indian Ocean territory of Diego Garcia. In July 2007, the UK Intelligence and Security Committee said it had found no evidence [JURIST report] of direct UK involvement in the operation of the extraordinary rendition flights through UK airspace, and said that the United States' lack of regard for UK concerns in the war on terror had "serious implications for the working of the relationship between the US and UK intelligence and security agencies." In August 2006, the former head of the British domestic spy agency MI5 [official website] refused to testify [JURIST report] before a joint parliamentary human rights committee investigating UK anti-terrorism practices.