A group of eco-activists who invaded a power station have been sensationally cleared of criminal damage.

The six Greenpeace protestors were accused of causing £30,000 damage after they climbed a tower at Kingsnorth Power Station, in Hoo, and painted the word "Gordon" on it last October.

They did not deny writing the word but argued that their actions were justified because, by closing the E.ON owned plant, they saved £1 million worth of damage to the environment.

Today a jury at Maidstone Crown Court accepted their argument by a 10-2 majority.

The defence case included testimony from leading scientists, including NASA climate expert James Hansen.

Michael Wolkind QC, defending, welcomed the verdict, saying the protest had been a mercy mission for the planet.

He said:"These defendants did not climb the Kingsnorth chimney for fun.

"The painted message was an SOS - the future of the planet is in real and immediate danger.

"Their acquittal must make the government change their policy on coal production.

"As Prof Jim Hansen said - it's an opportunity for Gordon Brown to step forward and take a leadership role in the world.

"If the amount of carbon in the atmosphere is not immediately and substantially reduced, we will pass a point of no return by 2015 or even sooner."

Ben Stewart, from Lyminge near Folkestone, was one of the Greenpeace protesters who scaled the chimney as part of an attempted takeover at Kingsnorth Power Station on October 8 2007.

He said: "This verdict marks a tipping point for the climate change movement. If a Kent jury say it's legitimate for a direct action group to shut down a coal coal-fired power station because of the harm it does to our planet, then where does that leave government energy policy."

Kent Police Chief Constable Mike Fuller said the force would be considering the implications of the verdict with the Crown Prosecution Service.

Asst Chief Constable Allyn Thomas from Kent Police, added:

He said: "We worked closely with the Crown Prosecution Service to bring this case before the court.

"We accept the jury's decision and should any further evidence come to light, we will review the case."

E.ON spokesman Emily Highmore, said: "We are extremely disappointed with today's verdict.

"While we are support of peoples' right to protest, it is clearly unacceptable for anyone to behave in a way that fundamentally puts peoples' lives at risk.

"The UK needs an open and honest debate about the challenges we are facing, not just about climate change, but also about the issue of energy, security and affordability."

The protest was led by 47-year-old Tim Hewke of Chegworth Road, Ulcombe, and also included: Kevin Drake, 43, of High Street, Chapmanslade, Wiltshire; Ben Stewart, 33, of Alkham Road, Stoke Newington; William Rose, 27, of Laurier Road, Kentish Town; Emily Hall, 33, of Smyrna Road, Kilburn; and Huw Williams, 40, of Chesterfield Drive, Burton Joyce, Nottinghamshire.