Five Conservative-led councils have been granted permission to challenge Sadiq Khan’s intention to expand London’s Ultra Low Emission Zone. 

The outer-London boroughs of Bexley, Bromley, Harrow and Hillingdon along with Surrey County Council launched legal action in February over the proposed extension of ULEZ beyond the North and South Circular roads.

Hillingdon borders Buckinghamshire to the east of Denham. 

A judge at the High Court has now decided their bid for a judicial review can go ahead, saying parts of the local authorities’ challenge were “arguable”.

Sir Ross Cranston, in a written decision issued on Wednesday, said a one-day hearing should be held in early July.

If it goes ahead, ULEZ will see drivers in outer London pay a £12.50 daily fee from August 29 if their vehicles do not meet the required emissions standards.

The new borders will reach Buckinghamshire, Essex, Hertfordshire, Kent and Surrey.

READ MORE: Wycombe MP Steve Baker calls out ULEZ expansion to Bucks border

Councils involved in the legal challenge believe “relevant statutory requirements” were not complied with, expected compliance rates in outer London were not considered and the proposed scrappage scheme was not consulted on.

They also claimed the overall consultation process was not properly conducted and there was a failure to carry out a cost-benefit analysis of the plan.

The High Court has allowed the case to proceed on two grounds – the legal basis for the scheme and scrappage.

A spokesperson for the mayor said: “The mayor is pleased to see the court has refused permission for the majority of the grounds.

“We will continue to robustly defend his life-saving decision to expand the ULEZ and continue with preparations without delay.

“It is a shame that some local authorities have chosen to attempt this costly and misguided legal challenge instead of focusing on the health of those they represent.

“Around 4,000 Londoners die prematurely every year due to air pollution.

“This is a health emergency and the mayor is not prepared to stand by and do nothing while Londoners are growing up with stunted lungs and are more at risk of heart disease, cancer and dementia due to our toxic air.”

Paul Osborn, leader of Harrow Council, said: “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.”

Nick Rogers AM, 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, which take money from charities, small businesses and low-income Londoners who cannot afford a new car.

“Sadiq Khan should do the right thing, immediately stop work on his ULEZ expansion and explain his actions to the court.”

It is unknown if Buckinghamshire Council, which is outside of Greater London, will challenge.

Last week, Wycombe MP Steve Baker criticised the expansion plan as a ‘money grab’.

He also expressed concern over financial impact on residents forced to travel to the ULEZ area during times outside of public transport such as Heathrow in the emission zone.