Freedom of expression is very important, so I propose a compromise. Display as much advertising and other propaganda as you like, but no actual burning of fossil fuels is allowed anywhere within city limits. Temporary exceptions to be made for fire trucks, construction equipment, and essential freight deliveries so long as it can be show that there is no current alternative and there’s a credible plan to create one within five years.
Maximum rationalisation mode: Maybe Conservatives will now be so confident that they’ve already won the next election that those of them who are just feigning the hate for trans people, gays, immigrants, refugees, socialists, liberals, opponents of fascism, and whatever other scapegoats they can find in order to win popular support will feel that they can safely tone it down a little and just coast to victory without needing to stir up even more fear and anger.