More than 1,400 vehicles were seized by bailiffs in 12 months for non-payment of London’s ultra low emission zone (Ulez) fees, figures show.
Transport for London (TfL) said a total of 1,429 cars were removed from their owners in the year to the end of July.
Some 761 were auctioned, recovering £710,000 of debts accrued by drivers refusing to pay the Ulez charge.
Mayor of London Sadiq Khan made the Ulez area almost four times larger by covering all the capital’s boroughs on August 29 last year, creating the world’s biggest pollution charging zone.
At the time, he said it was “a difficult decision” but insisted it was vital to tackle air pollution.
For petrol cars to meet Ulez standards – based on emissions of nitrogen oxides (NOx) and particulate matter – they must generally have been first registered after 2005.
Most diesel cars registered after September 2015 are also exempt from the charge.
Drivers who enter the zone in a non-compliant vehicle are required to pay a £12.50 daily fee unless they are exempt, such as taxis or transport for disabled people.
Failing to pay the charge by midnight on the third day following a journey risks incurring a penalty charge notice (PCN) for £180, reduced to £90 if paid within 14 days.
Ignoring this leads to the sum increasing to £270, and eventually TfL can apply for a court-issued warrant to take action to recover debts, such as using bailiffs.
TfL said £25.6 million of debt was recouped over 12 months.
It gave examples of a driver with 45 warrants against them settling a balance of nearly £16,000 in July after being traced to a new address, and another with 21 warrants making payments of more than £7,800.
The organisation said it is tripling the size of its investigations team to boost its work with enforcement agents.
An anti-Ulez Facebook group with more than 45,000 members urges people to refuse to pay Ulez PCNs, and praises vandalism of the scheme’s enforcement cameras.
TfL’s chief customer and strategy officer, Alex Williams, said: “The most recent data shows that on average, over 96% of vehicles seen driving in the Ulez are compliant.
“We want to send a clear message to vehicle owners that if you receive a penalty charge for driving in the zone, you should not ignore it.
“Your penalty will progress to enforcement agents to recover the fines that you owe, and there is a risk that your vehicle and other items of property will be removed.
“The aim of the Ulez is to clean up London’s air and remove old polluting cars from the road so no drivers need to pay and no fines occur.
“There is only a small minority of drivers who are eligible for the charge, and even fewer who are refusing to pay – but we encourage anyone experiencing financial difficulties not to ignore PCNs, and to engage with our staff, who will work with you towards a resolution, including setting up debt payment plans.”