Five councils, including four in Greater London, have joined together to launch a judicial review into plans to expand the Ulez to outer London boroughs.

The London boroughs of Bexley, Bromley, Harrow and Hillingdon and Surrey County Council have brought the legal action, it was revealed on Thursday.

The councils plan to challenge Transport for London (TfL) and the Mayor of London’s decision to expand the Ultra Low Emission Zone to outer boroughs by August.

The local authorities have vocally opposed expansion, believing it will do little to improve air quality and would add more costs for residents already struggling with the cost of living crisis.

The coalition is challenging the expansion in the High Court on five grounds, claiming that TfL failed to compy with statutory requirements or consider compliance rates in outer London.

The group of councils also claimed that the proposed “scrappage scheme” was not consulted on, and no cost benefit analysis was carried out. It claimed there was “inadequate consultation”.

But a spokesperson for the Mayor of London said neither the Greater London Authority nor TfL had yet been served with the legal claim.

“We will be defending any challenge to this vital scheme,” the spokesperson said.

Councillor Baroness O’Neill of Bexley OBE, Leader of the London Borough of Bexley, said: “We have been clear from the start that we believe air quality is important but that Ulez is the wrong solution.

“We believe he should give the monies that he has allocated to Ulez to the boroughs who actually understand outer London and the transport connectivity problems our residents face to come up with innovative solutions that will deliver better, more practical results.”

Leader of Hillingdon Council Ian Edwards claimed that the Ulez scheme has “negligible or nil impact on air quality”, while Leader of Bromley Council, Colin Smith, described it as a “socially regressive tax”.

Leader of Surrey County Council Tim Oliver added: “ We are dismayed at the lack of discussion or consideration given to these proposals by the Mayor of London.

“It’s disappointing that we, along with other local authorities, have to resort to legal proceedings to try and bring the Mayor of London to the table, but we have no choice but to do so.”

The legal action was announced just hours after the UK’s biggest union, Unite, also called on Sadiq Khan to halt expansion of the Ulez.

The union fears it will impact around 20,000 workers at Heathrow Airport who often drive to work due to unsociable hours, according to the BBC.

Unite spokesperson Joe McGowan said: “The outcome of this is profoundly anti-worker. We expect the party of the worker to stand by working people.”

On Wednesday Boris Johnson came out in support of Hillingdon Council in opposing the Ulez expansion.

“It will hit hardworking families and businesses in outer London with an unfair tax grab,” the former prime minister said.

Mr Khan plans to expand the Ulez zone to cover all of Greater London by the end of August this year. He claims five million more Londoners will breathe cleaner air if the Ulez expands for a second time.

The Ulez is an area of London that more polluting vehicles have to pay to enter. Drivers of older petrol or diesel cars have to pay TfL £12.50 for every day they cross into, or move within, the Ulez zone.

The Ulez was launched by Mr Khan in 2019 in central London. Two-and-a-half years later it expanded up to the edge of the North and South Circular Roads.

TfL’s most recent report found a 60 per cent reduction in the number of “non-compliant” vehicles being driven into or within inner London.

A spokesperson for the Mayor of London said: “While we’re aware of media speculation that an application for a Judicial Review has been made by four boroughs and Surrey County Council, neither the GLA nor TfL have been served with their claim.

“We will be defending any challenge to this vital scheme.

“Around 4,000 Londoners die prematurely every year due to air pollution. The Mayor is determined to protect the lives of Londoners who are growing up with stunted lungs and more at risk of heart disease, cancer and dementia due to our toxic air.

“The Mayor urges the councils involved to abandon this costly and unnecessary legal challenge and instead focus on the health of those they represent.”

In an interview with BBC Radio London this week, Mr Khan said: “In 10, 20 years time, people will look back at those opposing the Ulez expansion, and say they were on the wrong side of history.”