An inquiry into allegations of British security service complicity in the torture of terror suspects held overseas is expected to be announced imminently, after reports that Prime Minister David Cameron agreed details of how it will be conducted.
Mr Cameron is likely to be grilled about the inquiry when he appears for his weekly session of Prime Minister's Questions in the House of Commons.
But Downing Street would not be drawn on reports that the PM was planning to announce the details.
Foreign Secretary William Hague disclosed last month that the coalition Government agreed that there should be a "judge-led" investigation into the claims made by a series of detainees.
A No 10 spokeswoman said: "As the Foreign Secretary has said, there are important issues to be considered. An announcement will be made in due course."
However campaigners who were pressing for an investigation were in little doubt that there would be an announcement within days.
The pressure for an inquiry has been intensifying since the former Guantanamo Bay detainee Binyam Mohamed said he was tortured in Pakistan, while held by the CIA, with the knowledge of the British security services.
A number of former detainees since brought legal actions against the British government claiming similar treatment. The BBC reported that the inquiry will be able to offer compensation to people found to have been victims of torture with the knowledge of British intelligence officials.
Liberal Democrat MEP Baroness Ludford - the party's European human rights spokeswoman - said: "It's a breath of fresh air that the new Government is delivering on its promise to establish the truth about what happened regarding UK complicity in torture during the Bush years. This contrasts sharply with Labour denial and evasion."
Shami Chakrabarti, director of human rights group Liberty, said: "This investigation must be independent, judge-led and have broad powers to call evidence and make as much as possible publicly available. Only this kind of inquiry can end the slow bleed of embarrassing revelation and expensive litigation and draw a line under this shameful business once and for all."