George Bush must not be allowed to stand in the way of a new international agreement to combat climate change, a former Blairite cabinet minister told world leaders.
Stephen Byers, the former environment secretary, was at a world conference in Montreal to promote a policy that is guaranteed to infuriate US airlines.
He wants EU regulations on carbon emissions to apply to all US aircraft that use European airports - which would add millions of pounds to the cost of transatlantic flights, one of the most profitable sectors for the big US airlines. The proposal would force US operators either to cut carbon emissions, or pay a levy that will be used to reward European businesses that run clean operations.
The plan will be fiercely opposed by the Bush administration, and will ring alarm bells in Downing Street. Having persuaded George Bush to take part in talks on climate change at the Gleneagles summit in July, Tony Blair would like to keep the US involved in the process of cutting carbon emissions, although environmentalists have warned that trying to keep the US on side could make any meaningful agreement impossible.
Mr Byers, who now chairs the International Climate Change Taskforce, suggested a deadline of May 2009 for a new international agreement to replace the one reached in Kyoto, which runs out in 2012. The US has never signed the Kyoto protocol, which commits the nations involved to act to reduce carbon emissions, because its government says that it is bad for business. Mr Byers said that other nations should go ahead without them, hinting that US policy might change when the Bush presidency ends in January 2009.
"All around the world we are now witnessing the often-devastating effects of global warming," Mr Byers said. "Over the next 24 hours, a way forward needs to be found, here in Montreal, to deliver a post-2012 agreement. If phase one of Kyoto comes to an end without an adequate successor, our ability to avoid dangerous climate change will be dramatically diminished.
"The Bush Administration's statement that it will not be part of any new commitments on climate change shows that there is little to be gained by seeking to engage the US at this stage.
"The US could rejoin the international community's response to climate change after 2008, if the momentum continues to build for mandatory action to reduce emissions. That is why we have proposed a date of May 2009 for the completion of negotiations on what should happen after the first phase of the Kyoto protocol ends in 2012.
"Meanwhile, President Bush must not be allowed to block the rest of the world moving forwards in a meaningful way."
The EU is expected to introduce legislation by 2008 to bring European airlines into the "emissions trading" scheme, which has proved to be one of the most effective methods of holding down Europe's emissions of carbon.
Thousands of businesses in Europe, including US multinationals operating within the EU, are set limits to the amount of carbon they emit. Those that exceed the limit have to buy unused allocation from others that come below their limit. Mr Byers wants the same rules to apply to any aircraft landing or taking off from any European airport, including US airlines.
He said: "Recent research has shown that while the EU total greenhouse gas emissions fell three per cent from 1990 to 2002, emissions from international aviation increased by 70 per cent. The EU is right to extend its emissions trading scheme to cover aviation, but to be effective it must apply to all airlines flying to and from the EU airports and not just be restricted to European airlines."