Two Britons sentenced to death for fighting Russian forces in Ukraine plan to appeal against the verdict.

It comes as the family of one of the men, Aiden Aslin, say he has been told his execution will be carried out.

Mr Aslin, 28, originally from Newark in Nottinghamshire, and Shaun Pinner, 48, who has ties to Watford and Bedfordshire, have been treated as foreign “mercenaries” by authorities in the self-proclaimed Donetsk People’s Republic (DPR), who handed down the sentences to the two men who were fighting for the Ukrainian army.

Britain and their families argue they were legitimate members of the Ukrainian army who accordingly should be treated as prisoners of war under the Geneva Convention.

The two men have lived in Ukraine since before the invasion.

The Foreign Office on Thursday said it is doing everything possible to support the pair.

But the family of Mr Aslin told the BBC they have spoken to him on the phone and say he has been warned “time is running out”.

Watford Observer: Photo issued by the Foreign, Commonwealth & Development Office of Shaun PinnerPhoto issued by the Foreign, Commonwealth & Development Office of Shaun Pinner

A lawyer for Mr Pinner, Yulia Tserkovnikova, has told Russian news agency Tass that the verdict will be appealed.

She said: “My colleagues and I are working on the text of the appeal in the interests of our clients.

“If the appeal is rejected and the verdict comes into force, a request for pardon will be filed because it is the inalienable right of our clients based on the laws of the Donetsk People’s Republic. It must not be violated and they strongly insist on using it.”

A Foreign Office spokesperson told PA news agency: “We are doing everything we can to support the men and are in close contact with and helping their families.

“We condemn the exploitation of prisoners of war for political purposes and have raised this with Russia.

“We are in constant contact with the Government of Ukraine on their cases and are fully supportive of Ukraine in its efforts to get them released.”

No 10 described the sentencing as a “sham judgment” with “absolutely no legitimacy”.

Asked on Thursday if there was any update on any kind of agreement to bring the men home, possibly via a prisoner swap, the spokesman said: “That would be a question for the Ukrainian government.”