The mother of a journalist held hostage and brutally killed has called on the Home Secretary to work with the United States to bring two alleged so-called Islamic State militants, part of a group dubbed The Beatles, to trial.

The US has told Britain it will not insist on the death penalty for Alexanda Kotey and El Shafee Elsheikh, who are suspected of beheading Western hostages.

It could open the way for Britain to cooperate with the US in the sharing of information for any potential case against the pair, who are in US custody.

The decision was revealed in a letter to Home Secretary Priti Patel from US attorney general William Barr, and it is understood the move is seen as a welcome development by the Home Office.

Elsheikh and Kotey, who were caught in January 2018, are accused of belonging to a brutal four-man cell of executioners in Syria, nicknamed The Beatles because of their British accents, responsible for killing 27 captives.

Their capture sparked an international row over whether they should be returned to the UK for trial or face justice in another jurisdiction.

Other members of the cell are said to include Mohammed Emwazi, the group’s ringleader, also known as Jihadi John, who was killed in a US air strike in 2015, while Aine Davis is in jail in Turkey for terror offences.

Kotey and Elsheikh, who were raised in the UK but have been stripped of their British citizenship, were captured by the Syrian Democratic Forces in January 2018.

Emwazi appeared in a number of videos in which hostages, including British aid workers David Haines and Alan Henning and US journalists James Foley and Steven Sotloff, were killed.

The mother of Mr Foley has called on the Home Secretary to work with the US going forward.

Diane Foley told BBC Radio 4’s Today Programme: “We really implore the Home Secretary to consider this new decision and work together with the United States to bring these men to trial.”

She said it has been a “long journey to even find any people to hold accountable for these crimes”, adding: “These two men are only two of hundreds of people who’ve been involved in terrible human rights atrocities in Syria.”

Ms Foley told the programme: “I feel that the death penalty is too easy, allows them to be martyrs, if you will.

“And I really feel if they truly have done these horrible crimes they really need to face a life imprisonment.

“So they have a chance for redemption themselves, and a chance to really recognise the horror of what they’ve done to others.”

She said she is “very hopeful” that with the assurance the death penalty will be waived that it will allow the UK and US to pool their evidence “so that true justice might be served”.

In March, the Supreme Court heard a challenge over the UK’s decision to share evidence about the two suspected so-called Islamic State terrorists without receiving assurances they would not face the death penalty in the US.

A panel of seven justices ruled that then-home secretary Sajid Javid’s decision to share evidence with the US was unlawful and was made at a time when UK authorities were coming under “political pressure from the US”.

Ms Foley said it appears that the Department of Justice feels that the evidence that the UK has is essential, adding: “We want to have all evidence available for a trial.”

Asked about what she fears may happen if the men were to be released back to Iraqi custody, she said: “They could just escape, they could just go without being tried at all.

“Or they could be sent to the Iraqi courts. That, to me, we would lose a lot of the information they have and I fear there they probably would face the death penalty.”

According to the Associated Press, Mr Barr said in the letter: “I know that the United Kingdom shares our determination that there should be a full investigation and a criminal prosecution of Kotey and Elsheikh.”

AP reported that Mr Barr has made the UK aware that the US would press ahead with plans to transfer the men to the Iraqi criminal justice system for prosecution if American authorities do not soon receive the evidence that they seek.

According to AP, Mr Barr said the British government had until October 15 to resolve any legal objections and to provide US authorities with the evidence.

US officials have not announced any charges against Elsheikh and Kotey, but have spoken publicly about their desire to see members of the group face justice.

A Home Office spokesman said: “The Government’s priority has always been to protect national security and to deliver justice for the victims and their families.

“We continue to work closely with international partners to ensure that those who have committed crimes in the name of Daesh are brought to justice.”