麻豆社

Five Conservative councils are at the High Court trying to block the expansion of the Ultra Low Emission Zone (ULEZ).

The London authorities - Bexley, Bromley, Harrow, Hillingdon - and Surrey County Council are seeking a judicial review of London Mayor Sadiq Khan's decision to extend the ULEZ to outer London.

From 29 August, vehicles driving anywhere in the capital which don't comply with emissions standards will be liable to a 拢12.50 daily charge.

So what are the grounds for the legal challenge? What is the mayor's defence? And what could be the result.

麻豆社 Radio London's Ross Ryan has everything you need to know.