Downing Street has insisted that the Government continues to oppose the use of the death penalty, after it was revealed that Home Secretary Sajid Javid is not seeking a guarantee that two Britons will not face execution if extradited to the US for terror crimes.

A Number 10 spokeswoman said Prime Minister Theresa May was “made aware” of the decision not to seek a “death penalty assurance” in the case of two members of the Islamic State cell nicknamed The Beatles.

The decision was described as “extraordinary” by the Government’s former reviewer of terrorism legislation Lord Carlile, who said it amounted to a dramatic change of policy without any discussion in Parliament.

And Labour accused Mr Javid of “playing with the lives” of Britons all over the world by abandoning the UK’s blanket opposition to the death penalty.

The Downing Street spokeswoman said it was “a long-standing position of the Government to oppose the death penalty in all circumstances as a matter of principle”, but added that in this case it was “a priority to make sure that these men face criminal prosecution”.

Asked whether Mrs May approved of the letter, she replied: “The decision was taken by the Home Secretary and the former foreign secretary (Boris Johnson) and the PM was made aware of the decision.

“But, I would say, it’s everyone’s aim to make sure that these men face justice through a criminal prosecution.

“We are continuing to engage with the US government on this issue. We want to make sure that they face justice in the most appropriate jurisdiction which maximises the chance of a successful prosecution.”

Alexanda Kotey and El Shafee Elsheikh are said to have been members of the 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 1960s band because of their British accents, the cell is also believed to have included Mohammed Emwazi – known as “Jihadi John” – who was killed 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.

In his letter, obtained by the Daily Telegraph, Mr Javid told US Attorney General Jeff Sessions the UK “does not currently intend to request, nor actively encourage” the transfer of the pair to Britain.

Syria conflict
Alexanda Kotey, one of two Britons suspected of having been part of the Islamic State extremist group dubbed ‘The Beatles’ who were captured by Kurdish militia fighters in January (ITV News/PA)

Signalling that the UK was prepared to drop assurances relating to the death penalty, Mr Javid said: “All assistance and material will be provided on the condition that it may only be used for the purpose sought in that request, namely a federal criminal investigation or prosecution.

“Furthermore, 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.”

Mr Javid also said US courts were better placed to handle “foreign fighter” cases because of the risk of legal challenge in the UK.

The Telegraph reported that other documents say that Britain will not formally oppose a decision to send the men to the Guantanamo Bay detention facility without trial.

The letter sparked alarm in Westminster, with shadow attorney general Baroness Chakrabarti saying that Mr Javid appeared to have “secretly and unilaterally abandoned Britain’s opposition to the death penalty”.

She warned: “By doing so he is not just playing with the lives of these particular terrorists but those of other Britons – including potentially innocent ones – all over the world.”

Liberal Democrat home affairs spokesman Sir Ed Davey said: “The use of the death penalty – no matter the crimes involved – is wrong. By refusing to stand up to Donald Trump’s administration on this issue, Sajid Javid has abdicated his responsibility to uphold fundamental human rights.”

And Lord Carlile told BBC Radio 4’s Today programme: “It is a dramatic change of policy by a minister, secretly, without any discussion in Parliament.

“Britain has always said that it will pass information and intelligence, in appropriate cases, provided there is no death penalty. That is a decades-old policy and it is not for the Home Secretary to change that policy.”

Jihadi John named
Screen grab from footage issued by Islamic State militants of the British extremist Mohammed Emwazi, known by the nickname ‘Jihadi John’ (PA)

Amnesty International head of advocacy Allan Hogarth said Mr Javid should seek “cast-iron assurances” from the US that the two men will not be executed.

“While the alleged crimes of Alexanda Kotey and Shafee El-Sheikh are appalling, the UK’s principled opposition to the cruelty of the death penalty isn’t something it should compromise,” said Mr Hogarth.

“By refusing to seek assurances on this case, the Home Secretary is leaving the door wide open to charges of hypocrisy and double standards.”

Mr Foley’s mother, Diane, said she was opposed to the death penalty, warning it would make the two men “martyrs in their twisted ideology”.

“I would like them held accountable by being sent to prison for the rest of their lives,” she told Today.

A Home Office spokesman said: “We continue to engage with the US government on this issue, as we do on a range of national security issues and in the context of our joint determination to tackle international terrorism and combat violent extremism.

“The UK Government’s position on Guantanamo Bay is that the detention facility should close.”