Early on Tuesday, police officers invaded the makeshift encampment where 56-year-old Brian Haw had been living for more than five years.
They dismantled Haw’s array of banners and placards, some showing graphic images of the wars in Iraq and Afghanistan.
Haw vowed to continue his protest despite being left with only one poster.
"This is Mr. Blair's Britain," he said.
"You dare to speak, you dare to say it too real, too powerfully, to get through to people, and they smash it all down."
Haw began his protest in 2001 to protest against UN sanctions against Iraq and over time constructed a graphic display against wars and human rights violations around the world.
The anti-war camp had established itself as part of the London landscape, although it was not popular with many MPs.
London police said they removed the placards because Haw had failed to comply with a new law outlawing protests around the UK parliament.
The law, known as "Haw’s law," bans unauthorised demonstrations within a kilometre of the parliament building.
Earlier this month, a British court overturned a ruling that allowed Haw to continue his protest on the grounds that he began it before the law came into force.