Two Britons and a Moroccan who were captured while fighting for Ukraine and sentenced to death are preparing to appeal, Russia's TASS news agency cited one of their lawyers as saying on Thursday.
The court in the self-proclaimed breakaway Donetsk People's Republic (DPR), which is armed and supported financially by Russia, found the three men - Britons Aiden Aslin and Shaun Pinner and Moroccan Brahim Saadoun - guilty of "mercenary activities and committing actions aimed at seizing power and overthrowing the constitutional order of the DPR".
"My colleagues and I are currently preparing the full text of an appeal against the sentence in the interests of our defendants," TASS quoted Pinner's lawyer, Yulia Tserkovnikova, as saying.
"Undoubtedly, if the appeal is dismissed and the sentence comes into force, a request for clemency will be filed as this is an inherent right of the defendants, under the legislation of the Donetsk People's Republic," she added.
Reuters could not immediately reach Tserkovnikova.
The men's families deny that the trio, who were contracted to the Ukrainian armed forces, were mercenaries.
Britain has so far declined publicly to raise the issue with authorities in the DPR.
Mr Aslin's family told the BBC they had spoken to him in a phone call in which he said his captors had told him "time is running out".
"The bottom line is Aiden has said the DPR has told him nobody from the UK has made contact, and that he will be executed," the BBC quoted his grandmother Pamela Hall as saying.
"I have to believe what Aiden has said to us, that if the DPR don't get some response then they will execute him. Obviously I hope that isn't true."