The revelation that ministers have failed in their campaign to persuade the public that the greenhouse effect is a serious threat requiring urgent action will make uncomfortable reading for the Government as it prepares for next month’s climate change summit in Copenhagen.

Only 41 per cent accept as an established scientific fact that global warming is taking place and is largely man-made. Almost a third (32 per cent) believe that the link is not yet proved; 8 per cent say that it is environmentalist propaganda to blame man and 15 per cent say that the world is not warming.

Tory voters are more likely to doubt the scientific evidence that man is to blame. Only 38 per cent accept it, compared with 45 per cent of Labour supporters and 47 per cent of Liberal Democrat voters.

The high level of scepticism underlines the difficulty the Government will have in persuading the public to accept higher green taxes to help to meet Britain’s legally binding targets to cut carbon emissions by 34 per cent by 2020 and 80 per cent by 2050.