Kent owners of gas guzzlers are reeling over proposed car tax hikes.

From 2009-10 the most polluting cars in the county registered since 2001 will see their car tax more than double from £205 to £415.

That will mean an estimated £9.4m UK motorists paying more road tax, with the changes geared to hit gas guzzling cars.

Derek Linch, a Romney Marsh haulier, says the proposals are ridiculous.

He has already paid £400 on road tax on his Land Cruiser Toyota, £100 more than last year.

He said: "The Government is desperate to find ways to drag more money into the kitty and is using the environment as a smokescreen."

The knock-on effect is already being felt by some used-car dealers in the county with people opting to buy lower emission cars instead of bigger engine cars.

Roger Chapman, sales manager at Express Garage in Herne Bay, has noticed a 20 per cent increase in sales in these smaller engine cars over the last six months.

He says people are trading in bigger engine cars such as Hyundai 4x4s for cars like Daihatsu Sirions because they are more cost-effective.

“Bigger cars are losing value now as they are not worth as much as they were two months ago because of the new tax changes,” he said.

David Ferrett, owner of St Michael’s Garage in Sittingbourne, who is now buying fewer cars under two litres, said: “You can get fantastic performances out of these cars. Why do you need a four litre car?

“We are noticing people buying into a price range with low insurance and low road tax. It’s all Fiestas and small Seats and Polos at the moment because of increasing fuel costs and road tax pressures.”

Bigger car dealers, such as Barretts Land Rover in Canterbury, admit they are feeling the sting in customer preference, having seen sales drop by more than a third compared to last year.

But Andrew Thrush, the company’s dealer principal was confident business in time would adapt to the needs of the low emission market.

Mr Thrush said: “Our sales are suffering but Land Rover intends fully to respond to the need to reduce its carbon emissions and we have some very exciting products in the wings to make this happen. Land Rover has been working on new technologies for 2010 and beyond and new developments to deal with the pressure and adapt to the market.

“I think the Government is missing the point because there are so many cars on our roads that are poorly maintained. It’s not just our cars that should be targeted. Manufacturers need more time to develop new technologies as it’s a process of continuous improvement.”