A High Court challenge by five Conservative-led councils against Mayor of London Sadiq Khan’s plans to expand the capital’s ultra low emission zone (Ulez) will be heard on Tuesday.

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.

A judge at the High Court gave the councils the go-ahead to bring the legal challenge in April, saying parts of the local authorities’ challenge were “arguable”.

If it goes ahead, the expansion will mean drivers in outer London must 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.

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 that 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 at the time: “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.”

The hearing, before Mr Justice Swift, is due to start at 10am today (Tuesday) and the judge is expected to give his ruling at a later date.