David Cameron has defended a controversial decision to abandon a £1 billion programme to reduce Britain's carbon emissions, saying the economics of the plan "really aren't working".
Appearing before the Commons Liaison Committee, the Prime Minister said he had scrapped the plan for a large scale carbon capture and storage (CCS) plant because of the high costs, which would have been passed on to consumers.
Mr Cameron had previously told the same committee that CCS - which enables the burning of coal and gas without releasing damaging emissions into the atmosphere - was "absolutely crucial" to the UK's plans to reduce emissions.
But in his latest appearance, he said the costs had not come down in the way they had hoped.
"The economics at the moment really aren't working," he said.
"Even after you have spent that billion pounds, that doesn't give you carbon capture and storage that is competitive in the market.
"We hoped the cost would come down. You spend a billion pounds on the carbon capture and storage, you get some carbon capture and storage capacity and it would cost you at the current estimate something like £170 per megawatt hour.
"That compares with unabated gas costing £65, onshore wind perhaps costing £70 and nuclear costing, say, £90."
Mr Cameron angrily rejected suggestions the Government was "backsliding" on its green commitments following the international agreement last month in Paris to limit global warming to 2C.
"I totally disagree with anyone who says that on the one hand Britain has helped to pioneer this climate change agreement and on the other hand is somehow backsliding on its green commitments. It's total and utter nonsense," he said.
He said that 98% of Britain's solar panels had been installed since he became Prime Minister, while spending on solar power would double in this Parliament, compared to the previous coalition administration.
"Whether you look at solar or offshore wind - where we have the biggest offshore wind market anywhere in the world - whether you look at the Green Investment Bank, which is the first in the world, whether you look at the fact that we are reinvesting in our nuclear programme, whether you look at the fact that we are the first developed country to say that we are going to phase out coal-fired power stations, on any reasonable assessment, you would say that Britain is more than fulfilling its green commitments," he said.
Friends of the Earth chief executive officer Craig Bennett said: "If dismantling a dozen green policies and putting 19,000 solar workers on notice isn't 'backsliding on green commitments', I don't know what is.
"Cutting solar, banning onshore wind and privatising the Green Investment Bank, while letting frackers loose on our national parks, are not the actions of a government committed to meaningful climate action."