The Government’s bid to delay publication of its air quality plans until after the General Election has failed.

The deadline for final publication of air quality plans remains as 31 July.

Instead Ministers have been told they must produce the plans on 9 May after the local elections, with the deadline for the final plans remaining at 31 July.

The plans were due to be published by 24 April following a previous High Court ruling but following the announcement of the snap General Election, Defra applied for a last-minute extension, claiming that the general election purdah period meant that they could not publish their draft plans for consultation and requesting 30 June and 15 September as the respective extended deadlines.

During the hearing, James Eadie QC said that publishing the plans now would drop a “controversial bomb” into the mix of local and national elections.

However Mr Justice Garnham said Environment Secretary Andrea Leadsom was “obliged to comply with orders of this court as any other litigant” and added that air pollution had created “exceptional public health circumstances”.

The High Court judge also refused to grant permission to appeal, saying the Government would have to go direct to the Appeal Court.

Mayor of London Sadiq Khan greeted the decision, commenting: “Ministers were dragged kicking and screaming to face the huge scale of this health crisis, but rather than take immediate action to protect the public they deliberately used the election as a smokescreen to hold back their plan.

“I hope that after this appalling delay, this Government delivers a strong plan to finally get a grip on this issue and urgently introduces a diesel scrappage fund to rid our streets of the dirtiest cars, and provide financial incentives to encourage people to buy the cleanest vehicles.”