Transport for London (TfL) is earning nearly £220,000 a day from the new Ultra-Low Emission Zone (Ulez), which charges vehicles if they do not comply with strict pollution standards in the capital.

Read more: Sadiq Khan's Ulez charge lands: How much will London drivers pay?

Around 17,400 cars a day paid the £12.50 charge to enter into the Ulez zone in its first month, figures revealed today.

Ulez covers central London but mayor of London Sadiq Khan is due to expand it to cover the entire area between the North and South Circular roads in 2021.

The zone operates 24 hours a day, seven days a week, 365 days a year in the central London congestion charging zone.

Overall, one quarter of vehicles – 32,100 – in the capital remained non-compliant with London's new Ultra-Low Emission Zone (Ulez) in the first month since it was introduced.

Almost 12,000 of these cars were not required to pay the daily Ulez charge because they were eligible for a 100 per cent discount or exemption, such as black cabs, which do not have to pay the charge. The remaining 3,000 were issued with a warning notice.

Just under three quarters of those entering the Ulez zone, equivalent to 88,800 cars, were compliant with the new rules, and there were around 9,400 fewer "non-compliant vehicles" seen in the zone on an average day since the scheme began.

Khan said the numbers were evidence that "bold action reaps rewards".

Read more: How prepared are London boroughs for the ultra-low emissions zone?

"Just one month after launching the world’s first Ulez, leading the way for cities around the globe, we have already seen a significant impact on the types of vehicles driving in the centre of our capital and polluting our air. These were big changes, and vital ones – our toxic air is an invisible killer responsible for one of the biggest national health emergencies of our generation."