Police have cordoned off an area outside the Houses of Parliament after a climate activist climbed the walls of the Palace of Westminster.
A single protester climbed a pillar forming part of the Parliament building's defence.
He was wearing green trousers, a bomber jacket and a fake gas mask.
He was holding a stop sign with an Extinction Rebellion logo painted on it - and appeared to have a blue carrier bag with him.
The other side of the sign read “Let’s Go Green”.
A police helicopter hovered overhead while supporters chanted
“Extinction Rebellion”.
Dozens of police officers headed to Parliament Square while security teams inside the Parliamentary estate, including armed officers, stood guard.
Specialist climbing teams wearing abseiling equipment and climbing gear spoke to the protester, as activists chanted "Extinction Rebellion."
A 'cherrypicker' was brought in in a bid to coax the protester down.
And a 200ft cordon was set up to keep tourists and onlookers away from the scene.
The man was brought down from the wall and led away by police to cheers from watching protesters.
It is the latest security alert at Parliament and comes two weeks after a man tried to set himself on fire outside Carriage Gates.
A spokesperson for the Metropolitan Police said officers were "on the scene and dealing with it."
