The former shadow home secretary David Davis today demanded a Commons statement from the Government on accusations that British agents tortured a man held in Guantanamo Bay.
He also urged the Government to address an alleged US threat to withdraw intelligence sharing relations with Britain if details of the Binyam Mohamed case are released.
Mr Davis, raising a point of order, described it as "a matter of utmost national importance".
He told the Commons: "At 1.45pm today Lord Justice Thomas issued an astonishing ruling in the case of Binyam Mohamed, a British resident currently being held at Guantanamo bay and who has made an accusation of British involvement in torture inflicted on him while held in Afghanistan, Pakistan and Morocco.
"The ruling implies that torture has taken place in the Mohamed case, that British agencies may have been complicit, and most important of all, that the United States Government has threatened our High Courts that if it releases this information, the US Government will withdraw its intelligence co-operation with the United Kingdom on matters of security.
"The judge rules that there is a strong public interest that this information is put in the public domain even though it is politically embarrassing."
Mr Davis told MPs: "To quote directly from the judgment: 'It is plainly right that the details of the admissions in relation to the treatment of Binyam Mohamed as reported by officials of the United States Government should be brought into the public domain.
"'We did not consider that a democracy governed by the rule of law would expect a court in another democracy to suppress a summary of the evidence contained in reports by its own officials relevant to allegations of torture and cruel, inhumane, or degrading treatment, politically embarrassing though it might be.
"'We had no reason to anticipate there would be made a threat of the gravity of the kind made by the United States Government that it would reconsider its intelligence sharing relationship, when all the considerations in relation to open justice pointed to us providing a limited but important summary of the reports."'
Mr Davis said another part of the report "goes on to say that the Foreign Secretary has confirmed that this threat still remains under President Obama's new Government".
He called on the Deputy Speaker Sylvia Heal to "make representations" to the Foreign Secretary or Home Secretary to make a Commons statement today "about the involvement of British agents overseas in torture, and the right the United States Government has to block a British court from disclosing information given to it".
Ms Heal replied: "I have to inform the House that this is not a matter for the chair."