epa10763935 A sign announces the start of the London Ultra-Low Emission Zone (ULEZ) in London Britain, 23 July 2023. ULEZ was introduced in 2019 to tackle toxic air in the city by a taxing polluting vehicles. The environmental policy is thought be be a reason opposition Labour Party failed to win more seats in the bi-elections on 19 July 2023. Ahead of a possible 2024 general election UK political parties are publicly questioning green policy pledges in an attempt to chase populist voters. EPA-EFE/NEIL HALL