The High Court today ruled that US intelligence material on former Guantanamo Bay inmate Binyam Mohamed should be made public. Foreign Secretary David Miliband immediately said he would appeal.
Mr Miliband said the Government was "deeply disappointed" by the judgment. US authorities have strongly resisted the release of the material and the Foreign Secretary warned that the US may no longer be willing to share intelligence if it feared that it might later be disclosed on the orders of a foreign court.
In a statement, he said: "The Government is deeply disappointed by the judgment handed down today by the High Court which concludes that a summary of US intelligence material should be put into the public domain against their wishes. We will be appealing in the strongest possible terms."
In their ruling today, Lord Justice Thomas and Mr Justice Lloyd Jones said there was "overwhelming" public interest in now disclosing the seven paragraphs of material redacted from their original judgment on the Mohamed case last year.
"As the risk to national security, judged objectively on the evidence, is not a serious one, we should restore the redacted paragraphs to our first judgement," they said.
Mr Mohamed, now 31, was still being held at Guantanamo Bay awaiting trial at the time of the court's original judgment in August last year, but has since been released and has returned to the UK.
He is still fighting to prove that he was tortured and that the British authorities facilitated his detention and knew about the wrongdoing to which he was being subjected.
The judges have held it was clear from the fact that the UK intelligence services sought to interview Mr Mohamed during his detention and supplied information and questions for his interviews by others "that the relationship of the United Kingdom Government to the United States authorities in connection with Binyam Mohamed was far beyond that of a bystander or witness to the alleged wrongdoing".
Mr Mohamed, an Ethiopian, was granted refugee status in Britain in 1994. He was detained in Pakistan in 2002 on suspicion of involvement in terrorism and then "rendered" to Morocco and Afghanistan.
After being subjected to alleged torture by his US captors, he was sent to Guantanamo Bay in 2004.
The Government has come under increasing pressure to allow disclosure of material which could indicate how much M15 and Government officials knew about the treatment of Mr Mohamed.
The judges said they could not accept Mr Miliband's contention that the Obama administration was adopting the same stance as the Bush administration in relation to disclosure in threatening to withdraw intelligence co-operation.
And they could not accept there was anything of an intelligence nature in the redacted paragraphs relating to interrogation methods.
Commenting on today's court ruling, David Davis MP, who first raised the case in the House of Commons, said: "In an astounding judgment today, the High Court ruled that summary information about the treatment of Binyam Mohamed, the man who was tortured by a number of foreign countries with the complicity of the US and the UK, should be put in the public domain."
Mr Davis said the judges had rejected argument by Mr Miliband that the Obama administration were repeating threats by the Bush administration.
"They reject that assertion in magisterial terms, pointing out that it had no evidential basis," he said.
"They make it clear that the failure of the British Intelligence Services to provide all the appropriate documents, and the false evidence given by one witness, undermined the accuracy of their first judgment. This meant that judgment had, quite exceptionally, to be seriously amended.
"It is now time for the Government to accept the ruling of the court and stop trying to delay proceedings with further futile appeals.
"The British public have a right to know the judges' assessment of the extent of complicity of the UK and US Intelligence services in torture, and to determine for themselves why the Government has tried for so long to cover up this assessment."
Shami Chakrabarti, director of human rights organisation Liberty, said: "The Government should be shamed by this High Court finding suggesting that secrecy is being used to prevent political embarrassment about torture rather than to protect national security.
"In particular the finding that there was "no evidential basis" for the Foreign Secretary's assertion that (US) President (Barack) Obama was pressuring the UK should make Mr Miliband blush.
"Our courts should be gagged no longer and the crucial incriminating paragraphs published without delay. A full public inquiry into the darker side of Britain's war on terror becomes more inevitable by the day."
In separate pending High Court proceedings, seven former Guantanamo detainees - including Mr Mohamed - are bringing test case damages claims against MI5 and MI6, the Attorney General, the Foreign Office and the Home Office.
They allege that the security services were guilty, as part of a wider pattern of systemic misconduct, of "unlawful conduct amounting to domestic and international crimes in aiding and abetting the unlawful imprisonment, extraordinary rendition and torture" of each claimant.
Mr Mohamed claims that, in Morocco, he was severely beaten and subjected to sleep deprivation and that his genitals were cut with a scalpel.
At today's High Court hearing, Dinah Rose QC, for Mr Mohamed, told the judges that, although there might be some dispute over the interrogation techniques used on him, "everybody knows that he was being badly abused by the CIA and they told M15 about it".