The Mayor of London has announced plans to extend the city's Ultra-Low Emission Zone (ULEZ) to the whole of Greater London.
Sadiq Khan said in a speech on Friday that the policy would help tackle the "triple challenge" of air pollution, the climate emergency, and congestion.
Under the plans, from next year motorists in vehicles that do not meet emissions standards would have to pay £12.50 a day to drive in Greater London.
The policy already extends to the capital's north and south circular roads, taking in inner London.
The zone was extended to this point last year, having previously covered a smaller area in the centre of the capital. It operates in addition to the longstanding congestion charge.
The Mayor's office said extending the zone to the whole of Greater London would reduce NOx emissions from cars and vans by between 285 and 330 tonnes, cut CO2 emissions in outer London by between 135,000 to 150,000 tonnes, and reduce the most polluting cars on the roads by as many as 40,000 a day.
“The triple challenges of tackling toxic air pollution, the climate emergency and congestion mean we need to further reduce emissions from vehicles in London," Mr Khan said in his speech in Lewisham on Friday.
"We simply don’t have time to waste. The climate emergency means we only have a small window of opportunity left to reduce carbon emissions to help save the planet.
"And despite the world-leading progress we have made over the last few years, there is still far too much toxic air pollution permanently damaging the lungs of young Londoners and leading to thousands of deaths every year, with the greatest number of deaths attributable to air pollution in outer London boroughs."
The Mayor said the policy was "also a matter of social justice" because air pollution was "hitting the poorest communities the hardest".
"Nearly half of Londoners don’t own a car, but they are disproportionally feeling the damaging consequences polluting vehicles are causing," he said.
“If no additional action is taken to reduce air pollution beyond the existing polices, around 550,000 Londoners would develop diseases attributable to air pollution over the next 30 years and the cumulative cost to the NHS and the social care system is estimated to be £10.4 billion.
The policy was well-received by clean air groups. Sarah Woolnough, chief executive of Asthma + Lung UK, said the announced was a "landmark moment in protecting the lives and lungs of all Londoners".
"We now want to see this scheme put into action. For it to succeed there needs to be improved walking, cycling and public transport infrastructure in outer London boroughs so people are more confident to stop using their cars and transition to cleaner travel.”
Jemima Hartshorn, of the group Mums for Lungs, said: “Despite having campaigned for a London wide ULEZ since 2018, I did not dare to hope this would become reality soon. We know more about pollution and it's harmful health impacts, especially on children, now than we did a few years ago - so we urge all policymakers to not rest until pollution in London is reduced so far that it no longer shortens lives.”
Motorists can avoid paying the ULEZ by driving a cleaner car which meets modern standards – meaning the number of vehicles hit by the charge is likely to reduce over time as cars are replaced.
Adam Tyndall, programme director for transport at London First, said: “While expanding ULEZ will bring a welcome boost to air quality across the capital, it is disappointing that the Mayor is relying on a mechanism that will run out of road in the next few years.
"Simply incentivising Londoners to buy electric cars will do nothing to address the chronic congestion we see across London. We hope that this consultation leads to a more integrated scheme that is cost-effective for the essential road users and businesses who keep our city working.”
Mr Khan's administration had previously proposed a £3.50 boundary charge for all motor vehicles entering Greater London, but has since ruled this out. His office plans to consult on the ULEZ charge before implementing it.
Other suggestions from the mayor include support for pay-per-mile road pricing, though there are not as yet concrete plans for this approach.
But some campaigners have criticised the mayor for pushing ahead with the Silvertown road tunnel, which they say will encourage more pollution and congestion, and works against his other plans.
