How will it work?
Drivers will pay on the day, or in advance at garages, newsagents or shops. They will also be able to buy London permits on the phone or via the internet.

How much will it cost?
Five pounds per day, or part of a day. The charge will apply on weekdays between 7am and 7pm. Mr Livingstone intends to introduce the charge in 2003.

What area will be covered?
Proposed boundaries for the scheme extend from King's Cross in the north to Vauxhall in the south, and from Park Lane in the west to Tower Bridge in the east.

Will it be easy to dodge payment?
Mr Livingstone wants to install batteries of CCTV cameras which will record vehicle registration numbers. Evaders will be fined £100.

Any exemptions?
Motorcyclists, taxis, minicabs, buses and other forms of public transport.

How much will the charge raise?
Around 1m people work in central London, and during the busiest morning period more than 50,000 vehicles enter the city centre every hour. Even if the scheme reduces congestion by 15%, as Livingstone hopes, it will still rake in £200m a year.

What will that money be spent on?
Improved public transport. The strategic aim is to move away from ever-more elaborate road schemes which simply suck more traffic into the capital.

Does anyone object?
The shadow transport minister, Bernard Jenkin, has lambasted the scheme as "untested, unpopular, unworkable and unfair". Edmund King, executive director of the RAC Foundation, believes that congestion charges will be counterproductive, as they will tempt motorists into taking unsuitable alternative routes to avoid the charging area. Motorists do not seem too keen, either.