President Bush is preparing an astonishing U-turn on global warming, senior Washington sources say.
After years of trying to sabotage agreements to tackle climate change he is drawing up plans to control emissions of carbon dioxide and rapidly boost the use of renewable energy sources.
Administration insiders privately refer to the planned volte-face as Mr Bush's "Nixon goes to China moment", recalling how the former president amazed the world after years of refusing to deal with its Communist regime. Hardline global warming sceptics, however, are already publicly attacking the plans.
The rethink follows increasing pressure on the White House from Republican governors such as Arnold Schwarzenegger, the mayors of more than 300 cities, business leaders and Congress.
Over the past few days rumours swept the capital that the "Toxic Texan" would announce his conversion this week, in an attempt to reduce the impact of a major speech tomorrow by Al Gore on solutions to climate change.
The White House denied the timing, but did not deny that a change of policy was on its way. Sources say that the most likely moment is the President's State of the Union address in January.
Environmentalists expect the measures to fall far short of what is needed, but say this does not matter. "The very fact that Bush would reverse his position will liberate many Republicans to vote for meaningful pollution cuts," says Phil Clapp, president of the National Environmental Trust.
But Iain Murray, a senior fellow at the Competitive Enterprise Institute, Mr Bush's chief climate change cheerleader, is deeply alarmed: "We are left with the unpleasant conclusion that the only motivation is political."