London mayoral election: How has Sadiq Khan's Ulez scheme and other transport policies helped the capital?

Sadiq Khan likes to portray himself as the “greenest mayor ever”.

But how much of a difference has his flagship policy, the Ulez, made to air quality?

Has its controversial expansion to the Greater London boundary last August put his re-election in jeopardy? Could the Silvertown tunnel open up a new battle with the capital’s drivers?

City Hall Editor Ross Lydall looks at how his transport policies have affected the capital’s environment.

Is the air cleaner?

Yes. The London Air website, run by Imperial College, showed the capital covered in more than 50 red dots in 2016 — areas where pollution exceeded the recommended limits. By last year there were 12.

The Clean Air in London campaign group was so impressed it gave Mr Khan an A-rating for clean air in his