The number of diesel cars in Barnet could be contributing to a “health emergency”, new analysis shows.

Hundreds of doctors, nurses and health professionals wrote this week to prime minister Theresa May urging her to remove diesel vehicles as soon as possible.

Figures from the department of transport show of the 189,867 cars in Barnet and neighbouring Camden, 56,880 – or 30 per cent – are run on diesel.

This comes despite serious health warnings about the risks of cancer and air pollution.

Barnet Council has pledged to start collecting data on the use of diesel cars in the borough from April this year.

Chair of the environment committee Cllr Dean Cohen said: “We are already taking new measures to reduce pollution in Barnet by encouraging users to find greener ways of travelling.

“This includes providing free green parking permits to drivers of electric cars as well as introducing new charging points and car clubs.

“Barnet was awarded Cleaner Air Borough (CAB) status last October for effectively monitoring and reducing air pollution and a diesel surcharge will be introduced later this year.

“The proportion of diesel car users in Barnet is in line with the UK average, highlighting this is a national issue and not just a Barnet one.”

A 2014 report from Transport for London (TfL) said the growing popularity of diesel was a contributing factor in London’s failure to comply with EU air pollution limits.

Earlier this week, the campaign group Doctors Against Diesel said the vehicles could cause “irreversible lung damage” to children.

The government’s chief medical officer Professor Sally Davies has said diesel vehicles should be phased out.

Mayor of London Sadiq Khan has put proposals to the government for a scheme to compensate low income drivers switching cars to a cleaner model.

London assembly member for Barnet Andrew Dismore said: “Having almost 60,000 diesel cars on Barnet and Camden roads undoubtedly poses a significant risk to the health of residents.

“Many car owners will have bought diesel cars in good faith, when the evidence suggested diesel cars were better for the environment.

“With more recent evidence showing diesel to have numerous public health risks it is only right we do everything possible to reduce the number of these cars on our roads.”