A High Court judge is due to give his ruling over a legal challenge against Ulez expansion plans today.

Mr Justice Swift is expected to give the judgment at 10am (July 28) after five Conservative-led councils launched the bid to stop the expansion.

If it goes ahead, the extended 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 would reach Buckinghamshire, Essex, Hertfordshire, Kent and Surrey.

The outer London boroughs of Bexley, Bromley, Harrow, and Hillingdon, along with Surrey County Council began the legal action in February.

At a hearing earlier this month, the local authorities’ lawyers argued the Labour mayor lacked the legal power to order the expansion of the zone by varying existing regulations.

Craig Howell Williams KC, for the councils, said there was an “unfair and unlawful” approach to collecting views on the plans and that “key information… was not disclosed” during previous consultation.

The barrister added that plans for a £110 million scheme to provide grants supporting the scrapping of non-Ulez compliant vehicles were also unlawful because a “buffer zone” for “non-Londoners” affected by the extended charging zone was not considered.

Watford Observer: Mayor of London Sadiq Khan plans to expand the capital’s ultra low emission zone Mayor of London Sadiq Khan plans to expand the capital’s ultra low emission zone (Image: Aaron Chown/PA)

But the mayor’s legal team rejected the bid to quash his November 2022 decision to extend Ulez to all of London’s boroughs, arguing the move was “entirely lawful” and that “ample information” was provided for a “fair consultation”.

Ben Jaffey KC, representing the mayor and Transport for London (TfL) – an interested party in the case – said the “primary objective” of the Ulez expansion was “to improve London’s air quality, in particular reducing nitrogen oxides (NOx) and particulates”.

The barrister said Mr Khan’s decisions “will help to get London’s air quality closer to legal limits, where they are exceeded, and World Health Organisation guideline levels everywhere”.

Hertfordshire County Council also opposed the scheme, saying it would not allow Ulez signs or cameras within Hertfordshire.