High-polluting cars will have to pay £25 to enter London's congestion charge zone from later this year, it has been announced.
The move is the latest effort from the capital's mayor, Ken Livingstone, who is seeking to turn London into a clean air low carbon emission zone through this and similar measures.
From October 27th vehicles emitting over 225g of CO2 per kilometre will face the £25 charge. This includes the most high-powered four-by-four vehicles, sports cars and luxury vehicles.
Those emitting less than 120g of CO2 per kilometre will be rewarded with a 100 per cent discount. These account for only two per cent of all cars currently using the congestion charge zone, however, compared to 17 per cent for the highest-polluting vehicles.
"Nobody needs to damage the environment by driving a gas-guzzling Chelsea tractor in central London," Mr Livingstone said.
"The CO2 charge will encourage people to switch to cleaner vehicles or public transport and ensure that those who choose to carry on driving the most polluting vehicles help pay for the environmental damage they cause."
Mr Livingstone has grand ambitions for his scheme, which he hopes will encourage other cities around the world to adopt similar measures.
He added: "I think this scheme will also start a cultural revolution whereby drivers in every city in Britain start to think about the impact on the environment of their choice of car and how they plan their journeys."
Local businesses remain opposed to the congestion charge, which raises the cost of receiving goods. The Retail Motor Industry Federation (RMIF) points out most private cars in London drive outside the congestion charge.
The announcement has been welcomed by environmentalists and local pressure groups, however.
Green party mayoral candidate Sian Berry, a cofounder of the Alliance Against Urban 4x4s, said: "I am delighted with the level of public support for the emissions-based charge - this is [a] key policy we have called for since we began our campaign."