Home Secretary Sajid Javid has suspended co-operation with the United States over two terror suspects nicknamed The Beatles.
Mr Javid faced intense criticism after agreeing to share intelligence with the US without seeking assurances the men would not face execution if they were extradited.
MPs on all sides had accused him of breaching the UK’s long-standing opposition to the death penalty, while the Government’s former reviewer of anti-terror legislation Lord Carlile branded the move “extraordinary”.
The Home Office said it had agreed to a “short-term pause” of the mutual legal assistance (MLA) process with the US over Alexanda Kotey and El Shafee Elsheikh after a request from lawyers acting for one of the men.
A spokesman said: “Yesterday we received a request from the legal representative of the family of one of the suspects to pause the MLA response.
“We have agreed to a short-term pause. The Government remains committed to bringing these people to justice and we are confident we have acted in full accordance of the law and within the Government’s longstanding MLA policy.”
Kotey and Elsheikh are said to have been members of a brutal four-man cell of IS executioners in Syria and Iraq, responsible for killing a series of high-profile Western captives, including British aid workers David Haines and Alan Henning and US journalists James Foley and Steven Sotloff.
Nicknamed after the band because of their British accents, the cell is also believed to have included Mohammed Emwazi – known as “Jihadi John” – who was killed in a US air strike in 2015, and Aine Davis, who has been jailed in Turkey.
Kotey and Elsheikh, who are understood to have been stripped of their British citizenship, were captured in January, sparking a row over whether they should be returned to the UK for trial or face justice in another jurisdiction.
Prime Minister Theresa May supported Mr Javid’s original decision, which had also been backed by Boris Johnson when he was foreign secretary.
But the MLA sparked wide-spread criticism in Westminster from across the political divide.
A number of Tories raised concerns, with former attorney general Dominic Grieve warning the decision represented a “major departure from normal policy”.
Shadow attorney general Baroness Chakrabarti said Mr Javid appeared to have “secretly and unilaterally abandoned Britain’s opposition to the death penalty”.