The zone will extend to the boundary of the North and South Circular roads and operate around the clock, every day except Christmas Day. Non compliant vehicles face a daily charge of £12.50.

The expansion comes as Government this week set out its Net Zero Strategy which confirms plans to introduce a ‘zero emission vehicle mandate’ setting targets for a percentage of manufacturers’ new car and van sales to be zero emission each year from 2024. A consultation on the design of the mandate is expected to launch next year.

Government also committed an additional £620M to support the transition to electric vehicles, including the roll out of charging infrastructure.

It is thought that London’s larger Ultra Low Emission Zone zone will reduce harmful nitrogen dioxide across the capital by nearly a third. Mayor Sadiq Khan described London’s toxic air as “a health crisis causing long lasting harm to our children and contributing to thousands of premature deaths.”

He added: “The Ultra Low Emission Zone has already cut nitrogen dioxide pollution by nearly half in central London and the expansion of the zone on 25 October means many more Londoners across the city will enjoy the benefits of cleaner, healthier air.”

A £61M scrappage scheme for older polluting cars has seen more than 12,000 vehicles removed from the roads or retrofitted, City Hall says.

Clean air campaigning group Mums for Lungs co-founder Jemima Hartshorn told TP Weekly News: “We are so glad the Ultra Low Emission Zone is finally being expanded. In central London the ULEZ almost halved emissions, and we really hope the expansion will clean up the air more.”

She added that London's air is so toxic it is stunting lung growth in children, while exacerbating and causing asthma, cancer and cardiac issues. “But this is just the next step and will be nowhere near enough to ensure Londoners can breathe healthily and safely,” she added.

“For the health of our children we desperately need to see more effective action such as road user charging, a diesel free centre or the Zero Emission Zones the Mayor promised in his Transport Strategy.”

University of Birmingham clinical research fellow in environmental health Suzanne Bartington said expansion of the Ultra Low Emission Zone is a “welcome step forward for air quality and health.

“Air pollution is the largest environmental risk to health in London and is particularly harmful for the most vulnerable in society, including children, pregnant women and older people.” She added: “Introduction of the original ULEZ has reduced the number of children attending schools located in areas exceeding legal limits for nitrogen dioxide.

“Further action, including changes extending beyond the transport sector will be necessary to reduce air pollutant concentrations towards recently updated World Health Organization global air quality guidelines.”

Motoring group the RAC’s head of roads policy Nicholas Lyes commented: “While the majority will be unaffected by the expansion of the Ultra Low Emission Zone, around a fifth of vehicles don’t comply, so it’s vital drivers of cars, small vans and motorbikes use the Transport for London checker before 25 October or be prepared to pay a £12.50 daily charge.”

Commenting on the Government’s Net Zero Strategy – which reiterates several commitments from the Transport Decarbonisation Plan – Centre for London director of strategic projects Rob Whitehead said: “The guarantee that sales of new petrol and diesel car sales will end in 2030 will help to cut future carbon emissions, as will further funding for electric vehicle infrastructure.

“However we are unlikely to meet our net zero commitments without investing in a significant shift to journeys by public transport, walking and cycling, and other sustainable options like e-bikes and e-scooters.”

(Photograph: Transport for London)