As the UK government tries to quell a Labour rebellion against plans for a third runway at Heathrow, five young climate change protesters went on trial today at Westminster Magistrates Court in London. Leo Murray, Olivia Chessell, Alexander George, Tamsin Omond and Graham Thompson of the environmental group Plane Stupid are all being prosecuted under the Serious Organised Crime and Police Act for trespassing on a designated area when they staged a demonstration on the roof of the Palace of Westminster last February. The five protesters draped banners from the parapet saying ‘BAA HQ’ and ‘No third runway’. They also threw paper planes made from documents released under the Freedom of Information Act.

The five protesters are using a similar argument to the defence successfully used by Greenpeace earlier this year in a landmark case when protesters were cleared of causing £30,000 of criminal damage at a coal-fired power station. The Greenpeace protesters argued that they were legally justified in occupying the smokestack because they were trying to prevent climate change causing greater damage around the world.

Leo Murray, who is conducting his own defence, told the court today that Plane Stupid’s act of trespass was the ‘only truly effective remedy to a crime being committed’. He drew particular attention to the release of documents under the Freedom of Information Act that detailed discussions between BAA and the Department for Transport regarding the consultation over the third runway at Heathrow. Murray told the court that once he had seen the documents, he had concluded that ‘criminal wrongdoing was taking place’. He felt that going to the police would not be an effective course of action and that ‘it was necessary to commit minimal criminal activity in order to prevent a much more serious crime’.

The trial continues tomorrow. The consultation will report in the next few weeks on whether the government should go ahead with the third runway.