David Cameron's green agenda is 'spurious,' says Sir Jonathon Porritt

'It's shocking to see how cynical a politician can be,' says leading environmentalist of PM's attitude to climate change

Sir Jonathan Porritt is scathing about the Lib Dems (Rex)

Sir Jonathon Porritt, the former Green Party chairman, has launched a ferocious attack on the Government, branding its environmental record "disappointing and depressing". Sir Jonathon is scathing about David Cameron, Owen Paterson, the Environment Secretary, and the Liberal Democrats. But he reserves his strongest criticism for George Osborne, the Chancellor.

"The only words I can use to express my feelings about this government are that I have a deep sense of disappointment and depression. The spuriousness of Cameron's short-lived embrace of the green agenda prior to the election – it's shocking to see how cynical a politician can be," he said. Sir Jonathon is a former director of Friends of the Earth and founder director of the Forum for the Future sustainability charity.

"Osborne seems to be implacably hostile. It's baffling to me that most of the language we get from the Chancellor is negative to hostile rather than interested to enthusiastic. I just cannot understand that. There is something deeply disturbing going on in the Osborne brain that he just refuses to embrace the power of the green economy to drive prosperity."

Sir Jonathon has just published The World We Made, a book examining ways to put the planet on a sustainable footing by 2050. His concerns about the Government include coalition spats over issues such as the greening of Britain's electricity supply and environmental levies on energy bills, which raise serious questions over its commitment to low-carbon power.

Sir Jonathon also criticises Mr Paterson, whom it emerged last week has not been briefed on climate change by the Government's chief scientist since taking up his cabinet post 14 months ago.

"He is in every respect so sceptical about the potential impact of climate change that he can't even be bothered to get a proper briefing," Sir Jonathon said.

"There is a deep malaise in the middle of the Conservative Party that has just come to the conclusion that the green economy and the sustainability agenda has no place in their ideological world view and no traction with voters, so end of story."

Sir Jonathon is also withering about the Government's recent deal with France's EDF over the Hinkley Point C power station in Somerset: "The deal with EDF is so bad that... my bet is that this is going to come badly unstuck. I don't think we'll ever see any nuclear reactors built in this country.

"The inability of the Lib Dems to do anything to defend the green agenda has become more and more striking. I'm astonished they think this is something they are going to be able to hold their heads up about in the next election and say, 'Look what we achieved on energy' – including the whole volte face on nuclear, which is staggering," he added.

But Mr Cameron said: "This government has made huge steps forward in terms of environmental policy. We're the first government ever, anywhere, to set up a green investment bank… We've seen huge investments go into renewable energies… I think this has been a very sound government in terms of the environment."

A spokesman for the Department of Energy and Climate Change said: "Delivering a sustainable energy policy that tackles climate change, keeps the lights on, and helps people keep their bills down is a top priority."

Maria Eagle, Shadow Environment Secretary, said last night: "David Cameron's election call to 'vote blue, go green' because he intended to lead the 'greenest government ever' has been cruelly exposed as nothing more than a dodgy marketing trick from an ex-PR man."

A spokesman for Mr Paterson described at "nonsense" Sir Jonathon's comments about his lack of briefings. "The number of official briefings does not reflect the regular discussions the Secretary of State has had on all areas of his brief," he added.