The Government may bow to mounting pressure from green groups and opposition parties by bringing in a Climate Change Bill.
David Miliband, the Environment Secretary, is considering what a new law might achieve and there are growing signs that legislation may be included in the Queen's Speech on 15 November. Although no final decision has been taken, options include setting up an independent system to monitor progress in cutting carbon dioxide emissions and implementing measures in the Government's energy review, which will pave the way for a new generation of nuclear power stations.
Mr Miliband wants to ensure the proposed Bill has teeth and is more than just "gesture politics".
However, the move is unlikely to go as far as the Tories and Liberal Democrats have demanded. Ministers remain opposed to setting annual targets for cutting carbon dioxide emissions, saying they might be unworkable because of unforeseen circumstances such as a rise in gas prices which would push electricity companies into using more coal.
The Government also opposes a call by Friends of the Earth for ministers to be fined for missing environmental targets.
Yesterday Mr Miliband called for a cross-party consensus on tackling the threat to the planet. He told the Commons: "Climate change requires change right across society, from government, from individuals and from business. All these changes have met with scepticism, all with opposition, but they were right. Now we need to go further. We will do so, and I look forward to support from across the House in this drive."
He said the facts about climate change were "more alarming and the need for action more urgent than previously thought". He said carbon dioxide levels were higher than at any time for the past 740,000 years, 10 of the warmest years since 1850 had occurred since 1990, and global temperatures could rise by up to 5.8C by the end of the century.
Peter Ainsworth, the shadow Environment Secretary, was "delighted" the Government appeared to have shifted its opposition to a Bill. He said: "We need rolling annual carbon reduction targets to be agreed in Parliament; an independent body to assess the science and make recommendations as that evolves; and an annual report to Parliament to ensure ministers and civil servants are accountable."
But he faced charges of double standards after saying Tory MPs could oppose plans to build wind farms in their constituencies despite the party's support for renewable energy.
Mr Ainsworth insisted: "Individual members of parliament have a duty to represent their constituents' interests where they are affected by infrastructure projects of any kind.
"Conservative members are perfectly at liberty to take a view about proposals in their own constituencies. It doesn't actually affect Conservative Party policy."
Chris Huhne, said the Government liked to "talk the talk" on climate change but its policy was disjointed and dysfunctional.