A man was punched in the back of the head on a night out in Poulton.
The incident happened in the Cube bar earlier this month.
Police are now looking for a man captured on CCTV in connection with the assault.
The incident happened late on July 5 or in the early hours of July 6.
The victim was enjoying a night out in Poulton when he was approached by another man and punched in the head.
The attack took place between 11.30am and 1am.
The man police would like to speak to was caught on camera as he walked into the venue just before the incident occurred.
Officers are appealing for anyone who knows hime to come forward.
If you have any information on the incident or can help officers trace the man contact police on 101 quoting Crime Number WD1704386.