Brown to target gas guzzlers with taxes

Road tax is expected to be abolished for the "greenest" cars under plans in the Budget to encourage drivers to move away from gas-guzzling cars and four-wheel drive vehicles.

Mr Brown is likely to approve a radical shift in road tax, by imposing a new top rate of road tax - possibly up to £200 a year - on the worst-polluting new vehicles. In return, there are likely to be cuts in road-tax rates for low-emission cars and even frugal but middle-of-the-range vehicles which could see the lowest rate of road tax - currently £70 - waived entirely for vehicles with the lowest CO2 emissions.

Industry insiders expect the new top rate of road tax to be imposed on cars which pump out 200g to 250g of carbon dioxide per kilometre driven, a band designed to catch large cars and the so-called Chelsea tractors.

The new top band will be about £35 a year more than the current £165 maximum for petrol cars.