The Government has said it will publish a draft air quality plan by June 30, after the general election.
Speaking in the Commons on Monday, Andrea Leadsom, the secretary of state for environment, food and rural affairs, said that she is “deeply committed to the importance of ensuring clean air”.
However, she argued that the Government could not publish the its plan before the general election to comply with election "purdah" rules limiting Government announcements with political implications during the election period.
There has been speculation the clean air plan could include potentially controversial measures such as charges for motorists to drive diesel vehicles in towns and cities, or a diesel scrappage scheme.
The Department for Environment, Food and Rural Affairs (Defra) was ordered to rethink its approach for the second time in 18 months at the end of last year – after the High Court deemed its emissions modelling ‘too optimistic’.
The ruling followed a legal challenge by the environmental law firm Client Earth which claimed Defra had taken ‘minimum’ steps in order to comply with the EU directive on nitrogen dioxide emissions (NOx).
However, late on Friday, Defra lodged a fresh application with the High Court to postpone publication of its draft clean air plan – which the courts had ruled had to be published by 4pm yesterday (Monday, April 24) – until after the election.
The court is expected to make a decision in the next few days.