Gate-crashers left a man with a fractured skull after turning up uninvited to a wedding reception.
The victim also suffered a fractured eye socket and had three teeth knocked out in the savage attack.
City of London Police has released an image of a man they wish to speak to in connection with the incident of grievous bodily harm, which took place in the early hours of 14 October on Farringdon Street (EC4).
After entering the wedding reception uninvited, two men were asked by several guests to leave the premises. They refused to do so and became abusive to guests including the best man, father of the bride and another male.
After several minutes the two men were ejected from the venue but as they were leaving they grabbed hold of one of the guests and punched him to the floor. When on the floor, the two men stamped repeatedly on his head before walking off.
The man officers wish to speak with is approximately 6 foot tall, black, slim, and has long dreadlocks.
PC Ben Hurley said: “Violence of any kind will not be tolerated by the City of London Police and we would encourage anybody who recognises the man in the image released today to get in touch with us.
“This was a traumatic incident for the victim and numerous other people who had their special day ruined by violent strangers intent on causing trouble.
“It is vital we identify those responsible and bring them to justice.”