Drivers of gas-guzzling cars could be charged 25 pounds, about $47, a day to enter the central London's "congestion charge zone," under a global warming plan proposed by Mayor Ken Livingstone.
Under the proposals released Tuesday, the most polluting cars -- those that produce more than 225 grams of carbon dioxide per kilometer -- would attract the charge while the most eco-friendly vehicles (less than 120 grams) would travel free.
Other vehicles in the city's official congestion zone would continue to pay the usual flat rate of 8 pounds.
"Londoners are becoming increasingly aware of the need to tackle climate change and reduce CO2 emissions," Livingstone said in a statement. "Most vehicles that will be charged 25 pounds ... are high priced models. Those who buy them can afford to choose from pretty much the whole of the mainstream car market but have chosen to buy one of the most polluting vehicles."
Congestion zone expanding
Against widespread opposition, Livingstone introduced the congestion zone in 2003 and backed the zone's westward extension, due to start next year.
At present drivers entering the congestion zone between 6:30 a.m. and 7:00 p.m. weekdays must pay the 8 pounds a day or face a penalty of 50 pounds.
Livingstone has said although only 1 in 20 Londoners drive the most polluting cars, about 1 in 5 cars in the central congestion zone were of this type.
In August, a poll found that over two-thirds of Londoners backed Livingstone's plans to discourage the use of 4x4s, mockingly dubbed "Chelsea Tractors" after the wealthy London district where they are especially popular.
Suburb eyes parked cars
Last month, Richmond Borough Council in southwest London said it was proposing to charge residents who drive gas-guzzling cars significantly more to park outside their homes, in a bid to tackle pollution.
The local authority said it wanted to introduce a charging structure based on CO2 emissions. Owners of the most polluting cars could be face bills 200 percent higher.