Two northern MPs are taking the Government to court to demand an independent inquiry into the UK's complicity in torture after "years of dither and delay".
Barnsley Central MP, Labour's Dan Jarvis, and Conservative David Davis, who represents Haltemprice and Howden, are bringing legal action alongside the campaigning justice charity Reprieve, seeking a full judge-led inquiry into "the truth of the UK's role in post 9/11 abuses".
It is alleged the refusal to hold a hearing is contrary to Article Three of the European Convention on Human Rights, which requires governments to fully investigate credible torture allegations, and also violates the common law prohibition of torture.
The legal action comes after then-de facto deputy prime minister David Lidington told the Commons in July there is "no policy reason" and "no legal obligation" to hold an inquiry.
Last year the British Government issued an unprecedented apology to Libyan dissident Abdul Hakim Belhaj and his wife Fatima Boudchar over their rendition to the regime of dictator Muammar Gaddafi.
The couple say they were kidnapped in Thailand and taken to Tripoli in a joint MI6-CIA operation linked to Tony Blair's "deal in the desert" with Gaddafi.
Ms Boudchar, who was five months pregnant at the time, was released shortly before giving birth, but her husband was held in prison and tortured for six years.
Mr Belhaj was leader of the Libyan Islamic Fighting Group, part of the Islamist opposition to Gaddafi, said he was questioned by British agents during his incarceration.
Then prime minister Theresa May apologised to the couple for their "appalling" treatment and Ms Boudchar received a £500,000 payout.
Mrs May said: "The UK Government's actions contributed to your detention, rendition and suffering.
"We are profoundly sorry for the ordeal that you both suffered and our role in it."
Reprieve said: "Over nearly two decades, evidence of UK complicity has come out only in dribs and drabs, after repeated aborted investigations.
"Potentially hundreds of cases have never been fully investigated."
Mr Davis said in a statement: "When the Government finally admitted that it had no intention of holding a full and proper inquiry into torture, after years of dither and delay, I was frankly exasperated.
"Torture doesn't produce reliable intelligence, and involvement in it makes everyone in this country less safe.
"We must take a clear-eyed look at this dark period in our recent history, and give victims the redress and accountability they were promised, and face the future with a clear conscience and determination not to repeat the mistakes of the past."
Former PM David Cameron announced the so-called Gibson Inquiry in 2010 into the UK's complicity with torture, but the plans were scrapped two years later by former justice secretary Kenneth Clarke, who promised the inquiry would happen after police investigations finished.
But Mr Lidington told Parliament in July an inquiry was not needed "given the extensive work already undertaken to improve policies and practices in this area".
He added:"The Government's position is also that there is no legal obligation."
Former Army officer Mr Jarvis said: "We owe it to the victims, the public and our security services to find out the truth and confront our involvement in torture and rendition.
"Our response to the threat of terrorism must be unequivocal, but it must always be legal.
"As a country, we are not, nor should we ever be, above the law.
"Failure to hold an inquiry is unlawful, under British and international law."