Police have released an image of man that they are hunting in a bid to identify him.
On December 6, a 45-year-old Polish male was drinking with a friend in Charlies Bar, Neasden, when they befriended two other Polish males.
After a few hours an argument started and the men were separated.
The suspect, shown in the image, and his friend left the pub just after 11pm.
They were shortly followed by the victim and his friend who attacked the suspect.
When the victim tried to separate them he was punched once in the face by the suspect. He fell to the ground, unconscious in a pool of blood.
The suspect and his friend left the scene towards Cairnfield Avenue on foot.
The victim remains in hospital in a coma and his condition is described as stable.
Anyone who can assist police is asked to contact them on 101 quoting reference CRIS 1929512/14.
Alternatively contact Crimestoppers anonymously on 0800 555 111 or at www.crimestoppers-uk.org
