Failure to stop Chancellor from undermining efforts to cut carbon pollution and support for fracking means Lib Dems are no longer green, say charities

A coalition of environmental charities has launched a strongly-worded attack on the Liberal Democrats, accusing it of rapidly losing its identity as the mainstream green party.

In their first joint political assessment since the Tories came to power in May 2010, seven charities including RSPB, Greenpeace and WWF have combined forces to give a largely-damning verdict on all three of the big political parties.

They criticise David Cameron for failing to address what they describe as a growing scepticism about climate change in the Conservative Party and attack George Osborne for “framing environmental policy as an obstacle to growth, not as a route to prosperity”.

And they say that Labour has given “no sense that the environment is at the heart” of the party.

But the green alliance, which also includes the Wildlife Trusts and Friends of the Earth, reserves its strongest criticism for the Liberal Democrats.

The alliance said this is because the party has most closely aligned itself with green causes and because Nick Clegg told the Liberal Democrat conference last year that “We will hold [the Conservatives] to their promises on the environment.”

“Our review shows why the Liberal Democrats are fast losing their image as a 'green' political party. Their failure to stop the chancellor from undermining efforts to cut carbon pollution, and their support for fracking for more fossil fuels in the English countryside will have left many of their voters feeling betrayed,” said John Sauven, Greenpeace's executive director.

“It's a wonder that, given all this, Ed Miliband hasn't seized the initiative and given more attention to the coalition's failings on the environment and the potential for green jobs and growth,” he added.

David Nussbaum, chief executive of WWF-UK, said: “The green economy has bucked the trend of the recession and is the UK's strongest growth sector. But these areas need support, and mainstream political parties from each of the parties have failed to show visible and consistent leadership on the environment.

However, the charities' analysis was not entirely damning. The Liberal Democrats are praised for negotiating hard to set up the Green Investment Bank to help fund environmentally-friendly projects, persuading the Treasury to increase the amount of money available to invest in low-carbon electricity and for their commitment to green transport.

A number of Tory MPs - including the prime minister, foreign secretary William Hague and Greg Barker, the energy minister - are praised for being ”effective advocates for better policy in international forums“.

Meanwhile, Ed Miliband is credited with being the first leader to commit his party to a target of forcing the UK's electricity supply to become almost entirely green by 2030 - a policy which Liberal Democrat Energy Secretary Ed Davey attempted to insert into the Energy Bill passing through parliament, but which Mr Osborne removed. A subsequent vote on an amendment to put the so-called decarbonisation target back into the bill saw the Liberal Democrat MPs  ”whipped“ to vote against the target, even though it is contrary to party policy, the report notes.

A Liberal Democrat spokesperson said: "The Liberal Democrats take green issues incredibly seriously and are proud of our record in government, including investing billions in renewable energy and efficiency and creating the world's first Green Investment Bank. Since 2010 we've attracted over £29 billion of investment in renewable energy."

”However, we are not done. The Energy Bill sets out the plan for the creation of a low carbon electricity sector, which will ensure the 'lights stay on', that up to 200,000 green jobs are created and increases on consumers' bills are minimised,“ the spokesman added.

Separately, Natalie Bennett, the leader of the Green Party, will kick off her party conference in Brighton today with a plea to put climate change at the centre of the political agenda.

”This is a message for David Cameron, for Ed Miliband, for Barack Obama, for Xi Jinping, for Ban Ki-Moon, for every world leader, for every corporate CEO, for every person in the world today: We must start today…. to ensure that we'll preserve the world,“ she will say.