Britain's first ever Green Party MP has savaged David Cameron's claim to lead the "greenest government ever".
Caroline Lucas told HuffPost UK the coalition was casting the environment "as the enemy of growth" and sending out the wrong message on renewable energy.
She was speaking as a major new report warned that climate change was "unequivocal" and said scientists were more sure than ever that humans were to blame.
The much-anticipated report by the Intergovernmental Panel on Climate Change (IPCC) called for "substantial and sustained reductions of greenhouse gas emissions".
In 2006, David Cameron posed with huskies at a Norwegian glacier in a famous photocall as he attempted to cement his environmental credentials.
The Tories campaigned under the slogan 'vote blue, go green', Cameron had a wind turbine on his house and after taking office, pledged to lead "the greenest government ever".
Lucas is not impressed by the government's green credentials
Lucas, the MP for Brighton Pavilion, said: “Looking back at it now, it’s quite astonishing to contemplate that David Cameron could ever have talked about leading “the greenest government ever.
"Within eighteen months, it had tried to implement ill conceived planning reforms that cast the environment – and the regulation needed to protect it – as enemies of growth.
"And they’d undermined the solar energy industry with sudden and retrospective cuts to subsidies."
Attacking the expansion of shale gas, where she landed in trouble with criminal charges resulting from a protest in Sussex, Lucas went on: "Now we have the spectacle of subsidies being offered to shale oil firms, and the Prime Minister himself waving the flag for the fracking industry.
"It’s a far cry from his photo-shoot in the climate-change hit Arctic in 2006."
She also criticised Chancellor George Osborne, who said in 2011: "We’re not going to save the planet by putting our country out of business."
She called for more investment in green infrastructure and renewable energy, claiming this would create "thousands of green collar jobs".
The Department for Energy and Climate Change said it would be for Downing Street to respond to Lucas' attack on Cameron's record.
But responding to the IPCC report, climate change secretary Edward Davey was unequivocal: "The message of this report is clear - the Earth’s climate has warmed over the last century and man-made greenhouse gases have caused much of that global warming.
"The gases emitted now are accumulating in the atmosphere and so the solutions must be set in motion today. The risks and costs of doing nothing today are so great, only a deeply irresponsible government would be so negligent."
This will continue without "urgent action", he said.