An unprecedented coalition of blue-chip US companies and environmental lobby groups will urge President Bush next week to get serious about global warming, calling for caps on carbon dioxide emissions that would cut greenhouse gases by 10-30 per cent over 15 years.

The group, called the US Climate Action Partnership, will unveil the details of its plan on the eve of President Bush"s State of the Union speech on Tuesday. The companies involved include some of the old-fashioned pollution-generating industries normally associated with anti-environmental policies and politicians - the chemical giant DuPont, the bulldozer company Caterpillar, the aluminium producer Alcoa and the US subsidiary of BP.

They, and environmental lobby groups such as Environmental Defense and the Natural Resources Defense Council, said yesterday they will call for "swift federal action on reducing greenhouse gas emissions and speeding the adoption of climate-friendly technology".

The initiative was the latest of several indications of a big shift in US attitudes on global warming. The two-week-old new Democrat-led Congress has already generated a flurry of bills offering emissions-reduction targets. Nancy Pelosi, the new Speaker, is setting up a dedicated climate change committee in the House of Representatives with the power to recommend legislation.

Ms Pelosi has also promised a legislative package on energy independence, to be delivered by Indepedence Day on 4 July. Her enthusiasm is mirrored in the Senate by Barbara Boxer, the incoming chair of the Environment and Public Works Committee, who has called the fight against global warming her number-one priority.

The change in attitudes goes beyond the political arena. The star feature of the Detroit Auto Show last week was a plug-in hybrid vehicle being developed from General Motors.

The age of global warming denial, meanwhile, also appears to be drawing to a close. Exxon Mobil, the world"s largest oil company, has cut its funding to groups who argue global warming is a hoax, and is now working to develop strategies it can accept for emissions reduction.

That"s a huge change from just a few months ago, when Exxon Mobil"s chief executive, Lee Raymond, arguably the world"s most prominent global warming sceptic, was still at the helm, and the Senate Energy Committee was headed by the Oklahoma Republican James Inhofe, who made it his business to dismiss scientific opinion on climate change as a conspiracy.

The biggest hold-out against radical policy change is probably the Bush White House. Aides to the President have indicated his State of the Union speech will include some provisions on energy, notably championing the use of ethanol-based fuels. The administration remains opposed, however, to any mandatory caps on carbon dioxide emissions.

The White House is likely to come under increasing pressure to do something, however. One possible route has already been taken by Mr Bush"s fellow Republican, California"s Governor Arnold Schwarzenegger, who has endorsed a 25 per cent reduction in greenhouse gases in his state by the year 2020.

The Schwarzenegger plan does not operate on a rigid system of emissions caps, but rather offers incentives to companies who move faster than their competitors, who can "trade" their margin of emissions reduction with companies lagging behind. The "cap and trade" system contrasts with a bill championed by Senator Boxer, to mandate a reduction in emissions to 1990 levels by 2020.