More 'green' cars than gas-guzzlers will be sold in the UK this year for the first time as drivers respond to rising fuel prices and environmental concerns.

Sales of new cars in the £300-a-year top road tax band fell last year by 15% to the lowest level on record, according to figures from the Society of Motor Manufacturers and Traders.

Meanwhile, sales of low-emission cars in bands A and B, which are either zero-rated for road tax or pay £35, leapt by 17%.

Now, the SMMT is forecasting that sales of band G cars paying £300, such as the Porsche Cayenne and the BMW 7-Series, will continue to fall sharply and be overtaken this year by sales of cars in bands A and B.

Despite the publicity given to the Toyota Prius and other hybrid cars, which combine a petrol engine with an electric motor, most of the 128,646 low-emission cars sold last year had diesel engines.

The least polluting conventional car, which delivers an average of 72 mpg and emits 99 g/km of carbon dioxide - 5 g/km less than the Prius - is the diesel Volkswagen Polo Blue Motion, introduced last year.

The Government is planning to accelerate the shift to low-carbon cars with extra taxes on gas-guzzlers and concessions for the greenest models. The changes, which may include a widening of the price gap between each road tax band, are expected to be announced in the Budget in March.

Stephen Joseph, the director of the Campaign for Better Transport, said: 'The SMMT figures show people are already changing their car-buying habits. The market will adapt.' (The Times)