The scheme, which imposes daily charges on the owners of buses, vans, heavy goods vehicles and taxis that are driven in the city centre but do not meet emissions standards, has raised more than £4.5m for Bradford Council since it was launched in September last year.

According to a freedom of information response, the council had collected more than £2m from clean air zone (CAZ) payments by the end of March 2023.

But the council also issued 61,292 penalty charges to motorists who failed to pay and 60 per cent (36,834) had been paid by the end of March.

The clean air zone was launched in September last year

Anyone who misses the deadline to pay is fined £120 – reduced to £60 if paid within two weeks – and ordered to pay the outstanding CAZ charge.

The controversial scheme, which does not apply to cars and private motorbikes, is designed to reduce harmful levels of nitrogen dioxide. It covers an area within the city's inner ring road and the Shipley to Bradford corridor.

Owners of the worst-polluting buses, coaches and heavy goods vehicles must pay £50 a day to drive in the zone, while those with taxis, mini buses and vans that do not meet certain emissions standards are charged £7 a day.

Bradford Council said the amount of money generated by the scheme is expected to fall over time as fewer non-compliant vehicles enter the zone.

The council has also been handing out government-funded grants, to help drivers replace non-compliant vehicles.

Taxi drivers have been able to apply for up to £5,000 for a wheelchair-accessible petrol or diesel vehicle and up to £10,000 for an electric vehicle.

According to the Labour-run council, 98 per cent of the 4,000 licensed taxis and private hire vehicles in the district are now exempt from charges.

The Government ordered Bradford to set up the CAZ in 2020 due to long-standing concerns about harmful levels of air pollution. Zones have also been set up in cities such as Sheffield, Birmingham and Bath.

In Leeds, plans for a £29m Clean Air Zone were scrapped after the Leeds City Council warned it had “no legal authority” to go ahead with the project.

After several delays, a council official wrote to the Government in October 2021 and said the Clean Air Zone (CAZ) should be dropped, because the amount of nitrogen dioxide pollution on key roads was within the Government’s legal limit, following a significant reduction.

In emails, obtained by a Freedom of Information (FOI) request, he wrote: “If we were to continue to implement a CAZ having already achieved compliance and having evidence to show that compliance will be maintained, this exposes the council to legal challenge as the legal duty has now been met.”

Drivers in Yorkshire hit with 61,000 clean air zone fines over six months