Two people were arrested as tents and protesters were removed from Parliament Square, the Metropolitan Police said.
A spokesman for the force said officers arrived on the scene at about 7.30pm yesterday to remove "all tents and sleeping equipment from Parliament Square".
They finished the operation by 10.30pm, having cleared between eight and 10 tents and "moved on" 10 to 12 people.
Officers were enforcing the Police Reform and Social Responsibility Act of 2011, which gave police powers to prevent encampments around Parliament Square.
The spokesman said two people were arrested for breaching the act, and a third person was given a court summons for the same offence.
City of Westminster Council Clean Streets teams assisted officers in removing the protest camp, loading equipment into marked lorries.
The council proposed a new bye-law in December which would impose £500 fines for failure to remove the tents.
Council leader Colin Barrow expressed support for yesterday's police action.
He said: "For too long local people and tourists have been unable to fully enjoy the square.
"This is a tragedy and the sooner this historic site can be enjoyed by the public the better."
Police said some tents remained on the site, however.
"One person has launched legal proceedings. At the High Court yesterday the Met undertook not to enforce the legislation against that individual while proceedings are ongoing," the spokesman said.
Protesters - led initially by the late peace campaigner Brian Haw - have occupied the pavement opposite the Houses of Parliament for about a decade.
Campaigners set up Democracy Village on the green in May 2010.
They were evicted in July 2011 by the Greater London Authority following a High Court order, but some protesters then pitched tents on the pavement next to the lawn.
Suggested For You
SUBSCRIBE AND FOLLOW
Get top stories and blog posts emailed to me each day. Newsletters may offer personalized content or advertisements.Learn more