Anyone with an older car will now have to pay £24 simply to drive in London, following the introduction of a tough new “Ultra Low Emission Zone” on Monday by the mayor Sadiq Khan aimed at reducing pollution in the capital.

To the existing £11.50 congestion charge which applies to all cars entering central London between 7am and 6pm Monday to Friday, all vehicles that emit too much of the dangerous carbon monoxide or nitrogen oxides will have to pay £12.50 on top.

And unlike the congestion charge, the Ultra Low Emission Zone will operate 24 hours.

Non-compliant lorries, buses and coaches face a £100 daily fee.

In practice, diesel cars must be less than roughly four years old to avoid the charge, while petrol cars must be less than about 13 years old.

The penalty for breaking the law is £160 for motorists and £1,000 for lorry drivers, but this is reduced by half if the fine is paid within 14 days. The idea is to encourage more Londoners to use public transport. The London experiment is likely to be watched by cities all over the world where pollution has reached dangerous levels.

Sadiq said the scheme is being brought in because thousands of Londoners are dying early every year as a result of toxic air, with an increased risk of cancer, asthma, dementia and strokes.

He claimed the new charge will “help clean our air and reduce harmful road transport emissions”.

He commissioned a study by King’s College London and Imperial College London which found that poor air quality leads to about 1,000 London hospital admissions for asthma and serious lung conditions every year.

He said: “As someone who developed adult-onset asthma over the last few years, I know from personal experience that London’s toxic air is damaging people’s health.

“This study is a stark reminder that air pollution disproportionately affects the most vulnerable Londoners and I’m doing everything in my power to protect children, the elderly and those with respiratory conditions from our filthy air.” Initially the new charge will apply to the area of London covered by the congestion zone but will be extended to the whole of inner London within the North and South Circular roads from October 2021.

It is estimated that 100,000 cars, 35,000 vans and 3,000 lorries may be affected every day once the zone is expanded.

There is concern that poorer motorists, who cannot afford to upgrade their vehicles, will be disproportionately affected.

But it is also pointed out that pollution levels are higher in the poorer parts of London, even though the city jealously guards its many green spaces.

Eddie Curzon, the London director of the Confederation of British Industry, described the pollution charge as a “really positive step” but warned that “smaller firms can struggle to afford the switch to low-emission vehicles”.

Greater London Authority Conservative group leader Gareth Bacon claimed the mayor’s decision to bring forward the initiative by a year has “caught small businesses and charities on the hop”.

He added: “The damage caused by the early introduction of the central Ulez will pale into insignificance compared to the impact of its extension to the North and South Circulars in 2021. This punitive move will hit the very poorest Londoners hardest.”

To make his point, Sadiq, who faces re-election in May next year, spent Monday visiting children in hospital.