The London boroughs of Harrow, Hillingdon, Bexley and Bromley were joined by Surrey County Council in seeking to mount a legal roadblock against the mayor’s forthcoming expansion of the ultra-low emission zone.
He wants to extend the zone from the inner boundary of the North and South Circular roads across all 33 of the capital’s boroughs from August 29.
Drivers of vehicles that fail to meet the Ulez exhaust emission rules will have to pay £12.50 a day to enter or drive within Greater London if the expansion goes ahead.
About 200,000 non-compliant vehicles a day have been spotted in the outer London expansion area, though many more are registered to outer London addresses.
Ian Edwards, the Tory leader of Hillingdon council, told the Standard outside the court: “We have come together to represent our residents, who are outraged at Mayor Khan’s Ulez – a tax on living in outer London.”
He said public transport connections were poorer in the suburbs, meaning residents were more dependent on their cars.
“Our residents are telling us that low-income and elderly households are going to be most keenly impacted by this tax, as will local businesses,” Mr Edwards said.
“They are equally as concerned about air quality as Mayor Khan is but they know this isn’t about air quality. The Cleaner Cities Campaign have just published 13 air quality stations across London that didn’t meet the standards nationally. None of them were in any of our boroughs. The majority were in inner London.
“Mayor Khan needs to focus on tackling the problem and not focus on the wallets of our residents and local businesses. This is a taxation on life in outer London.”
Mr Khan was not in court. The case is being defended on his behalf by lawyers acting for Transport for London.
The judicial review hearing began with Craig Howell Williams KC, who is representing the five councils, requesting that some evidence provided by TfL be ruled inadmissible.
It was momentarily delayed when the judge told the court that his computer required him to enter a password to continue reading the legal documents.
The councils claim that Mr Khan acted beyond his powers – ultra vires in legal terms – in how he set out the expansion plans. Their case has three grounds, including that he failed to allow drivers living on the outskirts of London to access his £110m scrappage scheme.
They also allege that Transport for London failed to provide adequate data from its numberplate-reading cameras – meaning it was impossible to accurately assess the impact of the Ulez on a range of motorists.
The councils say Mr Khan should not have sought to establish the Ulez legally by varying the existing Ulez order but should have done so by drafting a brand new legal entity from scratch.
They will argue that the scale of the UIez expansion is “considerable” – being significantly larger than the existing zone and expecting to generate a net £200m a year in revenue from levies and fines.
Documents presented to the court by the councils claimed that the Ulez expansion decision was “unlawful” because it had not been drafted via a new charging scheme order.
“It is obvious that Parliament never intended this variation power to be used to introduce a whole new charging scheme,” the claimant’s argument claimed.
The councils accused the Mayor of an “unfair and unlawful consultation” in relation to expected compliance rates in outer London. TfL has been unable to say definitively how many motorists might have to pay the Ulez.
The consultation document claimed the outer London compliance rate would be 91 per cent of vehicles.
But the councils said the estimate – based on data from TfL’s camera network – may not have given a “representative picture”.
They said the consultation document was “unintelligible” and added: “Consultees simply were not told how the 91 per cent compliance rate had been calculated, which prevented them from being able to intelligently respond to it.”
Mr Howell Williams told the court: “The consultation must be fair and not be confused, not be misleading. It has to be complete. It must disclose relevant information.
“In sum, what must happen is there must be no detective exercise to be carried out, or paperchase, or puzzle to solve, and be sufficiently clear so that an intelligent response can be made.”
Opening the case for the five councils, Mr Howell Williams warned that a “cold towel” would be needed to help understand the intricacies of the case.
He said the original LEZ (low emission zone), which was introduced by Ken Livingstone in 2007 to target polluting lorries but not cars, had become “less perceptible” because of the many variations of the legal orders.
He said: “It’s been one variation upon another variation upon another variation. The original order is becoming obscured.”
The hearing, before Mr Justice Swift, is expected to last two days, with judgement likely to be handed down in the coming weeks.
Victory for Mr Khan will give the green light to the expansion going ahead at the end of next month.
But defeat could mean a delay of several weeks or possibly months, depending on the extent that the court finds flaws in the way Mr Khan and Transport for London went about preparing for the expansion.
The court cannot indefinitely prevent Mr Khan from expanding the Ulez but if he is forced to re-consult Londoners – which take many months to organise – that could turn the mayoral elections next May into a de facto referendum on the Ulez.
The hearing continues.