‘British citizens Aiden Aslin and Shaun Pinner, as well as Moroccan man Brahim Saadun, were sentenced to death by a pro-Moscow court in the Donetsk People's Republic earlier this month after surrendering in the besieged port city of Mariupol in April.
The court, which is not recognised internationally, sentenced the trio for acting as mercenaries and attempting to overthrow the government.
The ruling sparked outrage abroad where the European Court of Human Rights urged Russia to prevent the execution from going ahead.
In a rant on Russian state TV, nationalist MP Aleksey Zhuravlyov called the three men "b**tards" and promised that they would be executed "with a British weapon and a British bullet".
"I like the way the DPR is performing their international obligations," he said.
"As I was told, the shooting will be performed with a British weapon and a British bullet.’
