Despite strong sales of 4X4s (SUVs), over two-thirds of Londoners want motorists to be discouraged from driving large off-roaders in the capital, according to a poll on Friday.

Research by Ispos-MORI on behalf of the Greater London Authority (GLA) found 68% of Londoners would be happier with fewer SUVS on the city's congested streets, Reuters reported.

"Two thirds of Londoners back the idea that cars that do more damage to the environment should pay a higher congestion charge, and the same number want cars that do less damage to pay a lower charge," London mayor Ken Livingstone told Reuters.

Livingstone has proposed drivers of the least environmentally friendly vehicles should face charges of up to GBP25 a day to enter the capital's central congestion zone, compared with the current rate of GBP8 for all cars.

But the findings of the poll - conducted among 1,006 Londoners in July - contrast with actual sales of 4x4 vehicles, mockingly dubbed "Chelsea Tractors" by their critics after the upmarket London district where they are especially popular, Reuters noted.

Research in February showed Londoners were twice as likely as other Britons to buy off-roaders. One in six people in the capital who were looking to replace their car in 2006 said they would buy a 4x4, according to the AA.

Although there have been attempts by green groups to make driving a big 4x4 socially unacceptable, the national market for off-roaders remains strong, the news agency said.

Last year just over 187,000 were sold, representing 7.7% of the market, compared with 3.9% 10 years ago.