The victim was set upon outside Barclays Bank at the junction of Gowthorpe and Finkle Street at around 2:30 am, in the early hours of Sunday morning.
He was walking with a woman at the time of the attack where, as the pair turned into Finkle Street, they passed five men walking in the opposite direction. One of the men and the victim had a verbal altercation which lead to another member of the group punching him in the face.
The attack floored the victim who sustained serious injuries to his face. His jaw was split in two and he suffered a fracture higher up his jaw bone.
The victim was in hospital for three days where an operation was required to hold the victims chin together through the use of metal plates and screws that were inserted into his jaw.
The attacker is described as white and aged in his 20s. He is around 6 foot tall, with a slim build and fairish hair which was short on the sides. He was wearing a distinctive white t-shirt with a pattern on the front and black sleeves and possibly blue jeans.
It is believed that a number of people were in Finkle Street at the time of the incident and officers are urging any witnesses to come forward and help the investigation.
In particular officers are trying to trace two people who they believe may have vital information that can help them in their enquiries.
One is a man who helped the victim to his feet after the attack. He is described as white aged in his 20s, with a slim build and dark hair. He was wearing a grey hooded top with dark trousers and officers are urging him to come forward.
Another man officers want to trace is a man who watched the assault and then walked off down Finkle Street. He is described as white, with a slim build, and dark hair. He was wearing blue jeans with a long white t–shirt with a black jacket.
Anyone who can help the investigation is urged to contact North Yorkshire Police on 101 – select option 2 – and ask for Detective Constable Amanda Bostwick or Selby CID.
If you prefer not to give your name, Crimestoppers can be contacted anonymously on 0800 555 111. Please quote reference number 12140049856 when passing information about this incident.