One regular customer at Sir Robert Peel on Queens Crescent pub in Camden revealed that the stabbing took place and started over sharing the man chips.
Officers from the Met Police have erected a crime scene and a man has been taken to hospital following the pub fight on Saturday night.
Police ran from their vehicle with first aid kits that can be seen on the table near to the man chips wrapped in paper and gave him first aid before the arrival of paramedics. Crime scene officers have spent the late evening taking samples and collecting broken glass.
The attack took place just after 9pm on Saturday evening. The Met police have been approached for comment