A group of the UK's top business leaders have today issued their clearest call yet for the government to take bolder action on climate change, signalling support for deeper emission cuts, tighter environmental legislation and an expansion of carbon trading, and urging the prime minister to instigate a " transformational change" to the economy.

In an open letter to Gordon Brown, David Cameron and Nick Clegg, co-ordinated by the Prince of Wales' Corporate Leaders Group on Climate Change, the leaders of 18 major UK and international companies, including BAA, Centrica, E.ON, LloydsTSB, Shell, Tesco and Vodafone, called for a cross-party consensus "on the scale and speed of change required" to develop a low carbon economy.

The letter claims that, "climate change poses global social, environmental and economic risks and demands a transformational change in how we manage our economy. Incremental change will not do".

It also argues that the temptation to postpone costly low carbon investments in the face of a recession should be resisted. The global economic downturn may cause some to question whether the UK can afford to act so boldly," the group observes. "But we believe that action cannot be delayed, and furthermore, that decisive action will stimulate economic activity and job creation in certain key sectors as well as reduce costs in the medium to long term."

The group, which has written to political leaders in the past calling for a clearer low carbon policy framework, also offered its clearest indication yet of the measures it would like to see the government embrace, signalling its support for a wide ranging new legislative programme on the back of the imminent climate change bill.

In particular, it calls on the government to ensure that the targets in the climate change bill, which stand at a 60 per cent cut by 2050, "should be guided primarily by science, not short-term concerns over economic cycles". It also argues that it should be assumed that an international climate change deal will be agreed next year and as such, the EU will have to make good on its pledge to deliver a 30 per cent cut in emissions by 2020 as opposed to the 20 per cent cut that is currently proposed.

To help achieve such deep cuts, the group proposes an increase in the ambition shown by the proposed Carbon Reduction Commitment carbon trading scheme, alongside a huge rise in investment in low carbon technologies; the adoption of stringent new energy efficiency standards across a wide range of industries; increased spending on climate adaptation; financial incentives to promote greener products; and a greater emphasis on green public procurement.

Craig Bennett, co-director of the Corporate Leaders Group on Climate Change, said that the timing of the letter ahead of the passing of the climate change bill this autumn was intended to ensure that political momentum is maintained.

"There is a fear that politicians will say they have ticked the box with the climate change bill and move on," he said. "But what we need now are the comprehensive policy proposals to deliver real change… the issues are too big to rely on the free market and the reputational risk for businesses. We need government intervention to drive this shift towards a low carbon economy."

He added that a slowing economy should not be used as an "excuse not to act" , arguing that decisive action on climate change would stimulate the economy at a time when it is "certainly needed".

However, the letter brought immediate condemnation from Greenpeace, which accused several of the signatories of "hypocrisy of the purest strain".

"It is astounding that E.ON would call for action on climate change when they’re agitating to build Britain’s first coal-fired power stations in decades, " said Greenpeace communications director Ben Stewart. "It makes an environmentalist’s jaw drop to see the BAA logo on this letter when they're trying to expand airports across the nation... If the executives of these companies want action on climate change they should immediately lock themselves in their boardrooms and not come out until Kingsnorth and Heathrow expansions have been dropped."

A spokesman for E.ON hit back at Greenpeace's criticism describing its attack as "one of its more bizarre comments".

"Would they prefer it if we weren't a member [of the Corporate Leaders Group] and didn’t take climate change seriously?" he said. "E.ON is a 50 per cent partner in the London Array, has 21 on and offshore wind farms, is investing in marine and tidal energy, and building one of the world's largest combined heat and power plants. Just because we don't agree on one project, that does not mean we are ignoring our climate change responsibilities."

He added that E.ON was also fully supportive of the EU's emissions trading scheme and as a result, any emissions from the controversial Kingsnorth coal-fired power station would have to fit into the company's emissions cap.

Bennett also defended the right of carbon intensive firms to join the Corporate Leaders Group, arguing that while there was an on-going discussion both within the group and in the wider economy on how such industries will have to change in a low carbon economy, that did not mean they should be excluded from the debate.

"There is a wide range of opinions on what a low carbon economy will look like and the group has no single view on that," he said. "But what we can agree on is that climate change is happening, there is an urgent need to act, and that an economic slowdown is not an excuse not to act."