Greenpeace protestors on the British parliament roof. Greenpeace protesters on the British parliament roof.Photo: Greenpeace UK

LONDON — House of Commons authorities ordered an “urgent” probe Monday after dozens of climate change protesters scaled the roof of the British parliament as lawmakers returned from their summer break.

Twenty-three people were arrested and bailed by police after climbing up the landmark and unfurling a banner saying “Change the politics, save the climate.” They want urgent action before the U.N.’s crunch Copenhagen summit in December.

House of Commons speaker John Bercow told the first parliamentary session after a near three-month break that the security breach was being investigated urgently.

“We do not discuss matters of security in this chamber but I wanted to say to the house that I have had a preliminary report and the full circumstances are now being investigated urgently and thoroughly,” Bercow said.”Whatever action is necessary will be taken.”

Greenpeace protestor waves flag in front of Big Ben. A Greenpeace protester waves flag in front of Big Ben. Photo: Greenpeace UK

Around 25 people remain on the roof, from where Greenpeace employee Brikesh Singh, 29, from Bangalore in southern India, said: “We want them [lawmakers] to get the message loud and clear that if you want a planet-saving deal in Copenhagen, we need to change the climate policy.”

The December 7-18 United Nations climate summit in Copenhagen will see nations attempt to hammer out a new global climate treaty to replace the Kyoto Protocol which expires in 2012.

London’s Metropolitan Police said in a statement, “Twenty of the protesters who climbed onto the roof … have come down and been arrested on suspicion of trespassing on a protected site. They have been taken to a central London police station.” A further three were later arrested, a spokesman added afterwards.