The Attorney-General is considering asking the courts to clamp down on climate change protesters following the acquittal of six activists who shut down Kingsnorth Power Station.

A letter from the Crown Prosecution Service to lawyers for Greenpeace reveals the Attorney-General is close to referring the case of the Kingsnorth Six to the Court of Appeal in an effort to remove the defence of ‘lawful excuse’ from activists.

Greenpeace protesters Huw Williams, Kevin Drake, Ben Stewart, Tim Hewke, Emily Hall and William Rose walked free from Maidstone Crown Court in September.

~Listen: MP Ann Widdecombe talks on the rights and wrongs of the Kingsnorth protesters>>>

They faced a charge of criminal damage but successfully argued their 2007 chimney protest saved the planet millions in environmental damage caused by coal productio.

In October 2007 the Greenpeace volunteers had entered Kingsnorth coal-fired power station near Hoo, before scaling the chimney and painting Gordon Brown’s name down the smokestack.

In court they argued their actions were lawful because they were acting to protect property around the world from climate change.

Their defence team relied on section 36 of the Criminal Damage Act, which provides for a ‘lawful excuse’ to damage property in narrowly defined circumstances. The jury decided their actions were justified and the six were acquitted.

~Listen: Kingsnorth protester prepares to fight the government>>>

On Sunday the New York Times included the Kingsnorth defence in its annual list of the most influential ideas that will change our lives. The newspaper said the verdict ‘shook up the world of green politics.’

Now the government is seeking to establish a precedent preventing juries considering the ‘Kingsnorth defence’ for 'activists who face charges related to preventing emissions from entering the atmosphere in the course of non-violent direct action.'

Ben Stewart, one of the Kingsnorth Six, said: “Ministers have failed to grasp the point about our case.

After the acquittal they should have started dismantling plans for new coal-fired power stations instead of dismantling the jury system.

"Those twelve men and women sat through six days of evidence from international experts, and concluded we were justified in shutting down a coal plant because of the huge damage they do to our world.

"Now the government wants to shoot the messenger.”

Ben Stewart, one the Kingsnorth Six added: “[Environment Secretary]Ed Miliband has called for a people-led movement on global warming, but this government doesn’t trust normal people who sit on juries to decide what’s right and wrong on climate change.

"Ministers have set up citizens juries across the country on every issue under the sun, but when a real jury says something they don’t like on the greatest issue of our day, they move to shut them down. It’s pretty sinister.”

A final decision by the Attorney-General is expected in weeks. Any subsequent hearing at the Court of Appeal would follow in the spring.