Tony Blair has been accused of failing to set an example to the nation after refusing to give up his foreign holidays to help combat climate change.
The Prime Minister provoked a backlash led by Sir Jonathon Porritt, chairman of the Government's Sustainable Development Commission, who said Mr Blair's leadership on the issue in Britain had been "patchy and muddle-headed".
His attack stung Mr Blair into rushing out an announcement that carbon emissions from his personal air travel would now be "offset" as well as his official trips, starting with his new year break in Miami.
The Government has pledged to go "carbon neutral" by 2012 through "offsetting", which compensates for emissions by paying for green projects such as planting trees.
Downing Street said Mr Blair's move was a "logical extension" of the Government's policy of "offsetting" all official ministerial travel.
Mr Blair told a press conference last night: "This country leads the world both in terms of the issue of climate change and also meeting our Kyoto targets on the reduction of greenhouse gas emissions. But I am not going to be in the situation of saying I'm not going to take holidays abroad or use air travel. It's just not practical."
Earlier he sparked fierce criticism from green groups and opposition parties by giving a Sky News interview in which he refused to take breaks closer to home and said no politician would end cheap flights.
Sir Jonathon acknowledged that Mr Blair had done more than any other world leader to raise awareness about climate change but said there was "a complete failure" to show leadership on the issue in Britain.
He told BBC Radio 4 it was "completely wrong" for the Prime Minister to suggest scientists could be relied on to find a painless solution to global warming and to think that voters were unwilling to change their own behaviour."I am not saying Mr Blair should never take another foreign holiday, but I am saying that he should be looking carefully at the impacts of those holidays," he said.
Sir Jonathon accused Mr Blair of having "a policy of complete fatalistic despair" by arguing that Britain accounted for only 2 per cent of global carbon emissions. "If we are going to advise and influence other countries to reduce emissions, we have got to take the lead ourselves - in our own lives and as a nation through the economy," he said.
John Gummer, a former secretary of state for the environment , said Mr Blair's defence of his "shaming" long-haul trips was "a great dereliction of duty". Chris Huhne, environment spokesman for the Liberal Democrats, said Mr Blair's remarks showed he was "delusional" on climate change and that his environmentalism was only "skin deep".