A former British army soldier has been jailed for nearly eight years in Turkey after he was convicted of fighting against the Islamic State terror group alongside a banned Kurdish militia.

Joe Robinson, 25, formerly of Accrington, Lancashire, was sentenced to seven years and six months’ imprisonment for belonging to the YPG, a Kurdish armed group proscribed as terrorists by Turkish law.

He remains on bail and is planning an appeal against his conviction, his mother, Sharon Chimejczuk, told BBC News.

His fiancee, Mira Rojkan, was given a suspended sentence for “terrorism propaganda” after sharing Facebook posts with images of the Kurdish flag and links to Kurdish songs.

Robinson and Rojkan had been holidaying in south-west Turkey when they were detained on 22 July. Armed police swooped on the resort in Didim, about 62 miles (100km) north of Bodrum, where they were staying with Rojkan’s mother.

Their arrests came three years after Robinson, who served in Afghanistan in 2012 with the Duke of Lancaster’s regiment, travelled to Syria.

He spent about a month as a combat medic alongside YPG fighters battling against Isis before crossing into Iraq and joining the peshmerga, the Iraqi government-backed army of Kurdish fighters.

Turkey views the YPG – the armed wing of the Kurdish leftwing Democratic Union party in Syria – as an ally of the Kurdistan Workers Party (PKK), which has fought a decades-long insurgency against the Turkish state.

British police arrested Robinson at Manchester airport on suspicion of terrorist offences when he returned in November, but all charges were eventually dropped.