Police are hunting a man who punched a commuter repeatedly in the face for walking up the wrong side of the stairs at a Tube station in central London.

The 46-year-old victim was heading to the exit at Tottenham Court Road station walking up the right hand side of a set of stairs, when he was assaulted in broad daylight.

Detectives said his attacker pointed to a sign which said “keep left” before knocking him to the ground.

He was taken to hospital with heavy bruising to his face and a split left eyelid, which he still struggles to open, following the “unprovoked” assault on October 8.

British Transport Police are appealing for witnesses, and released a picture of the man they are trying to track down over the attack.

Detective Constable Dick Mortimer, the investigating officer, said: “The 46-year-old victim, from Plumstead, left a Tube train around 12.30pm and was walking up the right-hand side of a set of stairs at the station, towards the exit, when a man approached and pointed to a ‘keep left’ sign on the stairs.

“The man then punched the victim in the face, causing him to fall to the floor, before, as he regained his balance, punching him again.”

DC Mortimer added: “This was an entirely unprovoked attack on a man who was simply trying to leave the station. It appears the attacker was annoyed that the victim didn’t keep to the left while walking, but that is absolutely no excuse for his violent response.

“I would appeal to anyone who witnessed the incident, or who recognises the man pictured, to come forward and help officers in this investigation.”

Anyone with information is asked to contact British Transport Police on 0800 40 50 40 or Crimestoppers, anonymously, on 0800 555 111.