Jack Straw and David Blunkett were tonight facing questions about what they knew of a secret interrogation policy, devised in the aftermath of the 11 September attacks, which effectively led to British citizens being tortured during counter-terrorism investigations.
Both men were named in the Commons today by Ed Davey, the Liberal Democrats foreign affairs spokesman, who said that as foreign secretary and home secretary at the time they must have been responsible for approving the policy.
Yesterday the Guardian disclosed that Tony Blair knew of the existence of the policy drawn up to govern the actions of MI5 and MI6 officers when questioning detainees held overseas.
The officers were told they could not "be seen to condone" torture or take part in inhumane or degrading treatment of inmates, but were also told they were not obliged to intervene to prevent detainees being mistreated.
Legal experts said this policy almost certainly breached human rights laws.
Davey said it was "inconceivable" that Blair would be the only minister who knew about the secret policy, as Straw was the minister responsible for MI6, and Blunkett for MI5. "Either Straw or Blunkett, or possibly both, were also consulted and must also have given the green light."
Straw and Blunkett, responding to the Guardian's questions about what they knew, said in near-identical statements: "The British government unreservedly condemns the use of torture and its policy is not to participate in, encourage or condone the use of torture for any purpose.
"In light of the ongoing criminal and civil litigation, during which a number of the issues which you referred to in your letter, will be scrutinised by the courts and the police, I am not going to comment in detail on individual points or allegations."
Straw said he had followed government policy, condemning the use of torture "faithfully", while Blunkett added: "I reject absolutely that I authorised any action that I believed would lead to, or involve, torture."
Davey also said Blair should resign as Middle East peace envoy and "come clean" about his role in the policy guidance.
Andrew Tyrie, the Tory MP who chairs the all-party parliamentary group on extraordinary rendition, condemned the government's repeated refusal to investigate properly the allegations of serious abuses. "Getting to the truth is the only way to give the public confidence in current policies, to draw a line under all of this, and to move on."
There has been evidence of MI5 collusion in the torture of British terrorism suspects in Pakistan, where officers of the Inter-Services Intelligence Directorate were asked by MI5 to detain British citizens and question them. After the Guardian disclosed the existence of the interrogation policy in March, Gordon Brown said the policy was to be rewritten.