The cowardly attack happened around 3.30pm on Sunday as the 26-year-old victim walked through Cowal Park alone.

He is said to have been snuck up on by the brute who he heard shuffling behind him before he was struck by a heavy bottle.

The victim was taken to the Royal Alexandra Hospital in Paisley after suffering from lacerations to his head and neck.

Inspector Stevie Espie, of Johnstone Community Police, said forensic items had been seized at the scene.

He added: “We are following a positive line of enquiry in regards to finding the person responsible for the attack.” Anyone with information is urged to contact Police Scotland by phoning 101 or Crimestoppers on 0800 555 111.