London's new congestion charge plans - The Mayor's view

The consultation period on the proposals will run from August 10 to October 19.

After reviewing the comments, London Mayor Ken Livingstone will decide whether to press ahead with the revisions.

He said: 'Today marks the start of the consultation over this proposal, which aims to reduce the harmful emissions that cause global warming.

'By proposing these changes to the congestion charging scheme we are encouraging people to take into account the impact of their choice of car on the environment.'

The Mayor added: 'The highest carbon dioxide-emitting cars - like some of the so-called Chelsea tractors, high-powered sports cars and luxury executive cars - can produce twice as much carbon dioxide emissions as the kind of car driven by the average Londoner.

'We are already cleaning up London's fleet of public vehicles through measures such as the introduction of hybrid buses.

'These new proposals seek to tackle emissions from private vehicles and ensure that London is leading the way in the fight against catastrophic climate change.'