Police sprayed a man with a fire extinguisher outside Parliament Tuesday morning after he attempted to set alight to himself with petrol.
The man was just yards from one of the gates to the building when he reportedly covered himself in flammable liquid.
Police officers guarding the building quickly hosed him down with fire retardant as the man reached for a lighter.
A Brexit related placard was visible against the wall next to where the arrest took place, but it is unclear whether his actions were related to any protest.
A Met Police spokesman said: ‘At 10,44am, officers became aware of a man dousing himself with, what appeared to be, a flammable liquid at Old Carriage Gates, Westminster.
‘The man, who had a lighter, was sprayed with a fire extinguisher. There was no ignition and the man was detained.
‘The man was assessed by LAS and taken to a central London hospital. He has been detained under the Mental Health Act.