A man has spent almost a week in hospital after suffering serious head injuries in an attack on Christmas Eve.
The 38-year-old victim became involved in a verbal altercation with two men in Cromwell Road in Banbury, Oxfordshire.
The row became violent when one of the men punched him in the head twice causing him to fall to the floor.
He was taken to Horton Hospital but later transferred to the John Radcliffe Hospital where he is still undergoing specialist treatment.
The attacker is described as white, in his mid to late 20s, of medium build and between 5ft 7in and 5ft 9in.
He was wearing a grey woolly hat, tracksuit bottoms and a grey or blue tracksuit top.
Det Con Mike West, from Banbury CID, said: "This is a very serious incident that has left the victim with serious head injuries that have required prolonged hospital treatment.
"I would like to speak to anyone who was in the area who may have seen the incident, or anyone who may have seen a man matching this description in that area before or after the assault took place."