The family of Shaun Pinner, a British national handed the death penalty for fighting Russian forces have said they are “devastated” by the outcome of the “illegal show-trial”.

A statement issued on Saturday by the Foreign Office on behalf of the family of Mr Pinner, 48, said they are “saddened at the outcome of the illegal show trial”.

They added: “As a Ukrainian resident for over four years and contracted serving marine in the 36th Brigade, of which he is very proud, Shaun should be accorded all the rights of a prisoner of war according to the Geneva Convention and including full independent legal representation.

“We sincerely hope that all parties will co-operate urgently to ensure the safe release or exchange of Shaun. Our family, including his son and Ukrainian wife, love and miss him so much and our hearts go out to all the families involved in this awful situation.

“We respectfully ask for privacy from the media at this difficult time.”

Boris Johnson has ordered ministers to do “everything in their power” to secure the release of Mr Pinner, along with fellow Briton Aiden Aslin, 28, after the pair were condemned to death in what the UK Government has described as a “sham” sentencing.

Foreign Secretary Liz Truss discussed efforts to secure their release with her Ukrainian counterpart on Friday, after the judgment by a Russian proxy court.