Drivers of vehicles that do not meet strict emission standards could face a daily charge of £12.50 to drive anywhere in Greater London.

It's because London mayor Sadiq Khan has launched a consultation on plans to expand the ultra-low emission zone (ULEZ) to cover the whole of the capital.

Mr Khan says it could take more than 100,000 older, more polluting cars off the road as he bids to cut toxic air pollution and congestion.

He is proposing to extend the scheme’s boundary from the North and South Circular Roads to the whole of Greater London from August 29 next year.

Watford Observer: The current ULEZ boundary, up to but not including the North and South Circular roads. Credit: Transport for LondonThe current ULEZ boundary, up to but not including the North and South Circular roads. Credit: Transport for London

Speaking to the PA news agency at City Hall, Mr Khan said: "I’ve got a war on poisonous air. This is a war on climate change, this is a war on congestion to make sure that in London, everybody can breathe clean air.

"We’ve seen the benefits of the world’s first ultra low emission zone in central London and in London, we reduced by almost a half, the toxic air."

Whether or not a vehicle is liable for the ULEZ charge depends on how much nitrogen dioxide (NO2) it emits. For diesel cars to avoid the charge they must generally have been registered after September 2015, while most petrol models registered from 2005 are exempt.

In outer London more than four out of five vehicles are already compliant with the ULEZ standards, says TfL

City Hall said all Londoners live in areas that breach the World Health Organisation target for particulate matter and nitrogen dioxide, with 500,000 suffering from asthma and a similar number set to develop diseases linked to dirty air over the next 30 years.

Watford Observer: London mayor Sadiq Khan. Credit: PALondon mayor Sadiq Khan. Credit: PA

Oliver Lord, from the Clean Cities Campaign, said: "A London-wide ULEZ will ensure everyone breathes cleaner air and especially people living on busy arterial roads, who are often left behind.

"We are, however, long overdue a conversation on what comes next, and I’m pleased this has begun because we need to do more than the ULEZ to meet our climate goals."

Some politicians have criticised the Labour mayor's consultation plans.

Speaking in the Commons on Thursday, Conservative transport minister Andrew Stephenson said Mr Khan "must not punish people who need to use their cars, especially at a time when people are struggling with the cost of living".

On Friday morning, Sadiq Khan insisted that he would not press ahead with the plans if the public overwhelmingly rejected them during the public consultation.

Along with its environmental benefits, expanding the ULEZ would provide further income for Transport for London. TfL's finances have been strained as a result of the pandemic.

However, the BBC reported that expanding the ULEZ to the North and South Circular roads raised less income in its first month than expected.

Mr Khan previously ruled out introducing a Clean Air Charge, which would have affected drivers of all but the cleanest vehicles.

He also decided not to go ahead with a proposal to charge drivers of vehicles registered outside London for entering the capital.

The ULEZ expansion consultation ends on July 29. To take part visit https://haveyoursay.tfl.gov.uk/cleanair?cid=clean-air