Five councils have won the first stage of a legal challenge over Sadiq Khan’s decision to expand London’s ultra low emission zone (ULEZ).

The outer London boroughs – Bexley, Bromley, Harrow, Hillingdon – along with Surrey County Council teamed up to fight the mayor’s plans in February.

Today, it has been announced that the case will be going to High Court on two grounds – the failure to follow statutory procedures and failure of consultation over the scrappage scheme.

It is reported that the case is set to be heard in July.

The ULEZ is currently limited to the area within London’s North and South Circular roads, but is due to be extended to cover the whole of the capital from August 29.

It will then border areas of Buckinghamshire, Essex, Hertfordshire, Kent and Surrey.

Drivers of vehicles that do not meet minimum emissions standards will be charged a £12.50 daily fee for entering the zone.

However this ruling could potentially delay the planned expansion.

Nick Rogers, the City Hall Conservatives transport spokesperson, said: “The High Court has now ruled there is sufficient evidence that Sadiq Khan’s ULEZ decision may have been unlawful.

“The mayor clearly does not have the legal grounds to proceed with his ULEZ tax plans and must now explain his actions to the court.”

Conservatives in London also previously claimed City Hall officials “manipulated” the final results of Transport for London’s (TfL) consultation by excluding some so-called “campaign responses”, which lowered the level of opposition in the final count from 62% to 59%.

Cllr Paul Osborn, leader of Harrow Council said: “We said we would take this to court, and now we will get to present our case against the expansion of the ULEZ. 

“This is the first stage of the legal battle against the unpopular scheme which means the case will go to a hearing at the High Court. We are confident that the court will see how process was not followed through and proper steps not taken in relation to the scrappage scheme.

We have always had concerns about the impact ULEZ will have on our residents and businesses who are already struggling with the rising costs of living – it’s simply unfair!

“We will not back down on our fight against ULEZ and will continue to stand up for our residents.”