The fiancée of an ex-soldier sentenced in Turkey after joining a Kurdish armed group has called on Foreign Secretary Jeremy Hunt to intervene.
Joe Robinson, 25, from Leeds, was given a seven-and-a-half year jail sentence after volunteering with the YPG, which was fighting so-called Islamic State (IS) in Syria.
The group is regarded by Turkey as a terrorist organisation.
The Foreign Office said it had raised the case with Turkish authorities.
Robinson remains on bail pending an appeal against his sentence.
His Bulgarian fiancée Mira Rojkan, 23, was also arrested alongside Robinson while they were on holiday last year. She was given a suspended sentence for “terrorism propaganda”.
She said she wanted Turkey to rethink its treatment of her partner.
“The UK should stop saying they can’t do it, we know they can,” she said. “We’re talking about a veteran.
“He (Mr Hunt) needs to get in touch with the Turkish authorities on a diplomatic level.”
She said the family had written to former foreign secretaries Boris Johnson and Alan Duncan over the case, but hoped Mr Hunt would now intervene.
Robinson, who is originally from Accrington, Lancashire, said he only spent a month with the YPG while providing medical support to civilians in July 2015.
Miss Rojkan said Robinson was unaware of their ideology and did not see conflict.
Three months later, however, he did fight IS alongside Kurdish Peshmerga forces in Iraq, she said.
A Foreign Office (FCO) spokeswoman said officials were ready to provide Robinson with further assistance.
“We have been following this case very closely and have raised it with the Turkish authorities,” she said.