Brown tackles 'Chelsea tractors' in final Budget

Gordon Brown will answer critics of his record on the environment by raising the cost of driving gas-guzzling cars in his 11th and final Budget on Wednesday.

The Chancellor is expected to announce a shake-up of vehicle excise duty with higher rates for 4x4s or so-called "Chelsea tractors" to try to persuade motorists to switch to vehicles that cause less pollution.

Last week Mr Brown rejected punitive Tory proposals to increase the cost of flying through a "green air miles" scheme. Although the Chancellor regards that as a blunt instrument, he believes that road tax offers a more flexible way to cut carbon emissions because there are different rates for different vehicles.

Mr Brown will build on his announcement in last year's Budget, when he introduced a £210 annual road tax for the most polluting vehicles, a £40 rate for cars with low carbon emissions and a zero rate for a small number of cars with the lowest emissions. Other cars registered since March 2001 fall into bands with annual charges of £100, £125 and £150 and £190.

In a leaked memo to Mr Brown last autumn, David Miliband, the Environment Secretary, proposed a further hike for gas-guzzling vehicles after criticism that last year's Budget changes had not deterred enough people from buying them.

Mr Miliband said: "The success of company-car tax reforms in encouraging switching to more fuel-efficient vehicles has demonstrated the power of these levers. We can now expand this to the market more generally and explore a substantial increase in vehicle excise duty for higher-emission vehicles, aligning for all car owners the incentive to choose lower-emission cars."

Mr Brown was attracted to the idea but dropped it from his pre-Budget report in December after last-minute lobbying by the motor industry.

Opinion polls published yesterday showed that David Cameron is seen as "greener" than Mr Brown, but suggest that people are wary about paying more green taxes. A YouGov survey for The Sunday Times showed that 21 per cent of people regard the Tory leader as the "greener" of the two men, with 7 per cent citing the Chancellor. But 40 per cent said "neither" were green; 12 per cent said both were. and 20 per cent did not know who was greener.