But London Mayor Ken Livingstone said a daily charge of five pounds ($7) would be levied on motorists driving into the heart of the capital between 7 a.m. and 6.30 p.m.

The scheme, starting early next year, will use hundreds of cameras to check vehicle licence plates to ensure they have paid, and to enforce fines of 40 pounds or more.

Officials said 40,000 vehicles an hour drive into the taxable zone and the charge would cut this by 15 percent.

"The city has been pretty unliveable in many areas because of pollution, congestion and noise," Livingstone told reporters.

"I'd be lying if I said there won't be any problems, but they'll be dealt with as quick as we can," he added.

Singapore introduced a paper-based scheme more than two decades ago which is now electronic. Melbourne, Australia and Norwegian capital Oslo have toll charges for specific roads.

Emergency vehicles, motorcycles, buses and taxis will be exempt from London's scheme. Others, such as those living in the zone and the disabled, will qualify for a discount.

Critics say London's beleaguered public transport system must be improved before any congestion charge is levied.

"Congestion charging is untested in this country and to use central London as a pilot poses significant risks to its social, economic and environmental well-being," Kit Malthouse, deputy leader of Westminster council, which runs the heart of London, wrote in an open letter to Livingstone earlier this week.

Motoring organisation the AA said London drivers already pay three billion pounds in tax a year and 10 pence a mile in fuel tax.

"Transport in London is at breaking point. The only way out is major investment in public transport," the AA said.

Traffic in central London limps along at 9.9 mph (15 kph), the lowest average speed since before cars were invented.

The central London scheme could lead to a wider plan affecting the whole country.

The government-sponsored Commission for Integrated Transport announced proposals on Monday to make peak-time drivers pay for the privilege while persuading other motorists to move their journeys to times and routes attracting a lower tariff.