Current proposals will see ULEZ expanded to cover the whole city from August this year. The zone was first introduced in April 2019 and charges non-compliant vehicles – mostly diesel cars that are more than six years old and petrol cars that are more than 15 years old – £12.50 for each day they are in the zone.
Transport for London said that more than four in five vehicles in outer London, which would be affected by the expanded zone, already meet ULEZ standards.
The London boroughs of Bexley, Bromley, Harrow and Hillingdon and Surrey County Council have formed a coalition to mount a legal challenge against the action.
It includes allegations that the scheme fails to comply with statutory requirements and that the proposed scrappage scheme, which is designed to help people affected by the scheme to update their vehicles, was not consulted upon.
Councillor Ian Edwards, leader of Hillingdon Council, said: “Our position has remained unchanged from when TfL...