Drivers of some of the oldest and most polluting cars will have to pay a £10 'toxicity charge' to drive in central London from October.
The 'T-charge' will apply to drivers whose vehicles do not meet Euro 4 emission standards - typically petrol and diesel cars registered before 2006 - in the latest move by the mayor to crack down on air pollution.
Air pollution is linked to 9,000 early deaths a year in London, one of many places hit by the UK's air quality crisis, which has prompted the European Commission to issue a "final warning" to the Government for repeated breaches of legal limits.
One road in the capital exceeded its allowed annual levels of nitrogen dioxide just five days into 2017.
Check if your car is liable for an emissions surcharge by clicking here
Pollutants - much of which come from traffic, particularly diesel vehicles - cause health problems such as asthma, heart and lung diseases. They are also thought to affect children's health and development.
Up to 10,000 vehicles each weekday are expected to face the T-charge, which will operate on top of and during the same times as the congestion charge, so it will cost £21.50 to drive a pre-Euro 4 vehicle in the central London zone at those times.
It will be introduced on October 23, at the start of the autumn half-term, and will be in operation Mondays to Fridays, 7am to 6pm.
The mayor's plan has come under fire from Conservatives on the London Assembly who claim it will have only a 'negligible' impact on pollution,
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