Prospects for an early international agreement to tackle climate change have suffered a major setback, as a US plan to cut carbon emissions descended into partisan bickering.
Senior American political figures had promised to introduce a "cap and trade" energy bill today, paving the way for the kind of substantial international talks that failed to materialise at last year's Copenhagen summit, but the launch has been called off at the last minute.
Green groups expressed disappointment at the development, which supporters of the bill described as a "postponement", but the Republican Senator who had previously been on board stormed out on Saturday after what he called a betrayal by the White House.
Lindsey Graham said that President Barack Obama and Democrat leaders had decided to deprioritise the energy bill, and focus instead on trying to get an immigration reform bill passed. "This has destroyed my confidence that there will be a serious commitment and focus to move energy legislation this year," he said. "I will not allow our hard work to be rolled out in a manner that has no chance of success."
The Senator claimed a decision to prioritise immigration was a nakedly political attempt to mobilise the Hispanic vote for November's elections.
The White House, however, suggested Mr Graham's motives were also partisan. Larry Summers, the president's chief economic adviser, told CBS television's Face the Nation: "Even though immigration reform and energy reform are both crucial issues for the business community, there has been an enormous back-pressure against the kind of bipartisan co-operation that Senator Graham has engaged in, and that perhaps has made this a more complex situation, more difficult for him than it would otherwise be."
Senator Graham had been scheduled to help to unveil a bipartisan blueprint for energy reform today that would have introduce a limited cap and trade regime for utilities. He, Democrat John Kerry, and independent senator Joe Lieberman had been closing in on a compromise bill after months of talks aimed at forging a grand bargain linking emissions targets to incentives for nuclear and clean coal power and new offshore drilling permits.
Climate-change legislation has been stalled in Congress for months. The US has historically been the biggest producer of the carbon emissions responsible for global warming, although it has been surpassed by China. Although the House of Representatives passed a tough cap and trade bill last year after fraught negotiations with politicians representing coal-producing states, the Senate had made no progress.
It was that lack of progress that stymied the UN climate-change summit last December, because President Obama was unable to sign up to concrete targets for emissions reductions after the expiry of the Kyoto protocol in 2012. In the end, the summit offered only non-binding targets – with no guidance on how they should be achieved – and highlighted sharp disagreements between the US and China.
Environment ministers of the so-called Basic bloc – Brazil, South Africa, India and China – met in Cape Town at the weekend to look at how to fast-track a deal that would bind rich nations to cut emissions and reduce global warming. They said a legally binding global agreement to limit climate change needed to be completed by 2011 at the latest.
Senator Graham's participation in a US legislative effort had been seen as crucial to bringing on board the Republican votes needed for the measures to pass the Senate. His withdrawal is a serious blow.
But the White House promised to keep up pressure for progress in the Senate. Mr Obama's environment tsar, Carol Browner, said: "We have an historic opportunity to finally enact measures that will break our dependence on foreign oil, help create clean energy jobs and reduce carbon pollution. We're determined to see it happen this year."
Tom Picken, international climate campaigner for Friends of the Earth, said the delay means the US continues to be a "rogue state" in the climate-change consensus.
"What we are seeing in the US is a continuation of extremely negative influence on the UN climate policy, and this is the latest setback in what will be further poison to progress," Mr Picken said. "The US political and fossil-fuel lobbies are holding the world hostage by blocking meaningful progress. Crucially, international climate-change progress must continue within the official UN talks, with or without the US on board."