Local leaders from across the political spectrum have called on Philip Hammond to fill a £1.5bn black hole they argue exists in the funding needed to fight air pollution.

Ahead of next week’s Budget, 16 mayors, metro mayors and city leaders have told the chancellor that the £220m Clean Air Fund is 'inadequate' to fight a 'public health crisis’.

In their jointly written letter, the local leaders said the current Clean Air Fund is ‘now supporting many more cities than it was intended to’ with an additional eight councils now having to develop air quality plans.

This means up to 45 cities will now share the Clean Air Fund.

The letter’s signatories, brought together by the UK100 Cities Network, insisted that the funding committed by the Government to tackle air pollution is ‘simply inadequate on three fronts’.

There is ‘not enough funding for those local authority areas that the Government has identified as having the most severe air quality challenges, insufficient funding available for tackling the wider sources of air pollution and limited financial support for national measures,’ they wrote.

The leaders believe a £1.5bn cash injection — plus a targeted national vehicle renewal scheme prioritising the least well-off and small businesses — is crucial to cleaning up the country’s towns and cities.

It is estimated air pollution cuts short about 40,000 lives across the UK every year.

Polly Billington, director of UK100, said: ‘It is clear the current Clean Air Fund, while welcome, is not sufficient to tackle the problem of air pollution, which is shortening and worsening lives, pressuring public services and damaging the economy.

‘While we understand the Government has tough decisions to make on its spending priorities, the leaders are convinced acting now will enable the country to avoid the costs of ill-health and also enable us to shift to cleaner ways of travel, including boosting the manufacture and adoption of electric vehicles.

‘This should be taken seriously as a public health crisis but also viewed as an industrial opportunity that requires investment.’