Prime Minister Theresa May has hinted that concessions may be made for diesel car owners after London Mayor, Sadiq Khan, confirmed proposals for new emission charges. There were also reports that the government will introduce similar schemes in other cities.

She said: "Decisions will be taken when we produce that [air quality] plan. But I’m very conscious of the fact that past governments have encouraged people to buy diesel cars and we need to take that into account when we look at what we do in the future."

The Mayor of London is already introducing a £10 ’T-charge’ for the most polluting vehicles in October, and is proposing to introduce an Ultra Low Emission Zone (ULEZ) covering the same area as the existing congestion charging zone in 2019.

Petrol vehicles that don’t meet Euro 4 standards and diesel vehicles that do not meet Euro 6 standards will have to pay a ULEZ daily fee of £12.50 for cars, vans and motorbikes to drive in the zone.

This will affect petrol cars that are more than 13 years old in 2019, and diesel cars more than four years old in 2019.