Concerns over the economy are causing all three political parties in the UK to shy away from the green agenda for fear of alienating voters, according to a new report backed by the UK's largest environmental groups.

While the parties' rhetoric is sometimes impressive, it is often not supported with policy, and there appears to be a worrying lack of consistency, the report found.

"None of the three main parties are currently showing the vision and courage to prepare the UK for the challenges ahead," said Stephen Hale, director of Green Alliance. "In a time of rising fuel and food costs, the need for an ambitious approach to environmental policy has never been clearer."

The Alliance cites a Guardian/ICM poll from July as evidence that politicians' fears that the public are more concerned about the economy than the environment are misplaced.

That survey found that 52 per cent of respondents believed the government should prioritise environmental problems, with just 44 per cent claiming economic problems should be the top concern.

The Green Alliance - which includes Friends of the Earth, WWF and Greenpeace – is calling on the parties to re-commit to the green agenda at the upcoming party conferences and follow up their previous rhetoric over climate change with solid policy commitments.

"They must step up to the mark and commit to our proposals for action on energy efficiency, renewables, coal and aviation," said Hale. "There is no other credible alternative."

The report says that despite a steady increase in environmental legislation the government's approach to green issues has been "contradictory and incoherent ".

It argues that instead of using rising fuel prices as an opportunity to promote home generation and renewables, it has encouraged the view that there is a trade-off between economic and environmental objectives, citing energy minister Malcolm Wicks's recent claim that "We are not going to sacrifice fuel poverty on the altar of climate change".

Meanwhile, Conservative leader David Cameron is accused of holding green issues at arms' length after initially making the environmental agenda a key plank of his "decontamination" of the Tory brand.

Despite encouraging speeches and moderate opposition to new coal-fired power stations, the Conservatives have no clear plans or policies on tackling climate change, and at a press conference in May spelling out future priorities for the party, David Cameron failed to mention the environment at all.

The Alliance is concerned that a third of Tory MPs questioned by a ComRes survey in July questioned the existence of man-made climate change, and is also worried that an elected Conservative government would slowly return to this more traditional base.

In a recent interview, George Osborne said that green taxes would replace or complement existing taxes, rather than adding to them – an approach the Alliance praised because it does not set up the economy and the environment in opposition.

Last year, David Cameron appointed former Ecologist editor Zack Goldsmith as his chief environmental advisor, but when questioned recently said he was "one of many advisors" – effectively distancing himself from the green evangelist.

Meanwhile, the Liberal Democrat's bold announcement to make the UK energy-independent and zero-carbon by 2050 was welcomed by the alliance, but it again raised concerns that the party should have made the environmental issues a more central aspect of its attempts to differentiate itself from the two main parties in the past year.

The report's findings are likely to be seized on by opponents of environmental legislation as further evidence that green regulations will be sidelined as politicians seek to address growing economic concerns.

However, with all three major parties committed to passing the government's climate change bill this autumn, any attempts to back away from green issues are likely to be short-lived once legally binding emission reduction targets are formally adopted.