Owners of gas-guzzling cars could soon pay up to £25 a day to drive in the London congestion charge zone.

High performance sports cars and 4x4s may face the rise under consultation plans outlined today by Transport for London (TfL).

And not only could the owners of high emitting vehicles pay more than three times the current £8 a day congestion charge, they could also lose their entitlement to a residents' discount.

The city’s Mayor Ken Livingstone said there would be higher charges for vehicles "that make the biggest contribution to global warming".

Under the proposals, cars liable for the £25 per day charge would be those in Tax Band G and equivalent vehicles (above 225g of CO2 per kilometre) such as the Range Rover Sport and BMW M5 along with vehicles registered pre-March 2001 with engines larger than 3,000cc.

The congestion zone, recently extended into west London, covers parts of Westminster, Kensington and Chelsea.

Cars driving outside the present congestion charging zone will not be affected, while the highest carbon dioxide-emitting vehicles represent just 8% of cars registered in London.

The great majority of drivers within the zone would be unaffected, while the least-polluting vehicles will not pay any congestion charge at all.

According to a poll conducted by Mori for the mayor, 64 per cent of Londoners think the most polluting cars should pay a higher congestion charge.

The consultation starts on Friday and will end on October 19.

Mr Livingstone's office said the mayor would "keep an open mind on the proposals until he has considered the responses to the consultation".

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