Sadiq Khan is set to roll the scheme out across all 32 London boroughs on August 29 - with even his party leader Sir Keir Starmer voicing doubts about the idea.
Protest against ULEZ expansion featuring tractors and three-wheel car brings South London traffic to halt mylondon.news - get the latest breaking news, showbiz & celebrity photos, sport news & rumours, viral videos and top stories from mylondon.news Daily Mail and Mail on Sunday newspapers.
Tractors, a taxi and a three-wheel car were seen spiralling around a roundabout at Orpington War Memorial, south east London, while protesters shouted into megaphones and blew whistles.