A man has been arrested by armed police inside the Palace of Westminster.
The alleged intruder was spotted being held against a fence inside the Carriage Gates entrance to the Houses of Parliament, surrounded by around a dozen police officers.
Scotland Yard said the man had been detained on suspicion of trespassing at a protected site at around 11.55am this morning.
WATCH: talkRADIO's Ross Kempsell reports live from the scene
They confirmed a taser had been deployed, and said enquiries into the circumstances continue.
Photographs taken at the scene showed police pointing a gun at the man's head.
A clear plastic bag containing a pair of trainers could be seen on the ground nearby.
A statement from the House of Commons said: "We are aware of a situation outside the Palace of Westminster that was handled by the Met Police and is now contained.
"We cannot provide any further details."
The man has now been escorted away in a police van.