The Government has asked the courts for permission to delay the publication of plans to meet EU air quality standards until after the general election.  

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, just days before it was legally obliged to publish its revised plans which were rumoured to include a diesel scrappage scheme, Defra went to court on Friday seeking leave to delay it until after the June 8 general election, saying it was necessary "to comply with pre-election propriety rules".

The court is expected to make a decision in the next few days.