Captured jihadists Alexanda Kotey and Shafee El-Sheikh, who held British citizenship, are members of the “Beatles” group of Islamic State terrorists.
The Daily Telegraph cited documents showing that the UK government has abandoned its opposition to the death penalty so they can be sent to the US.
A letter sent by home secretary Sajid Javid to US attorney general Jeff Sessions says the UK would demand no “assurances” that the pair will not be executed, contrary to previous policy.
In the letter, dated 22 June 2018, Mr Javid said: “I am of the view that there are strong reasons for not requiring a death penalty assurance in this specific case, so no such assurances will be sought.
“I have instructed my officials to set out the terms of our assistance and to work with your officials to action the request.
“As you are aware, it is the long held position of the UK to seek death penalty assurances, and our decision in this case does not reflect a change in our policy on assistance in US death penalty cases generally, nor the UK Government’s stance on the global abolition of the death penalty.”
Other documents say that there would be no formal opposition to the two men being sent to Guantanamo without trial.
A senior Home Office source, however, was quoted in the newspaper as insisting that the US had been verbally warned against sending the two men to Guantanamo.
The source said: “We have proactively made it clear to the US that while we will share for the purposes of a criminal trial we will not for Guantanamo Bay.”
The home secretary’s letter reveals his fears that British laws may not be enough for a successful prosecution and that US terrorism laws will be more effective.
“Ensuring foreign fighters face justice raises a real challenge for all our jurisdictions, however in this instance we believe that a successful federal prosecution in the US is more likely to be possible because of differences in your statute book and the restrictions on challenges to the route by which defendants appear in US courts.
“The US currently has additional charges for terrorism offences which are not available under UK criminal law, and those offences carry long sentences.”
The terror cell was named the Beatles because its four members had British accents.
They were behind the beheadings of US journalists James Foley and Steven Sotloff, British aid workers David Haines and Alan Henning, and US humanitarian worker Peter Kassig.
The third member Mohammed Emwazi, who became known as “Jihadi John”, was killed by a drone strike in Syria in 2015 and the fourth, Aine Lesley Davis, is in a Turkish jail.
Kotey and El-Sheikh were captured in January and are being held by US-backed Syrian Democratic Forces.