EU law requires action to ensure air quality doesn't deteriorate to dangerous levels. Unfortunately, Boris doesn't let such trivia bother his tousled head, as we've pointed out on several previous occasions. Scrapping the twice-yearly taxi emissions check and delaying enhancements to the Low Emissions Zone have damaged air quality, as will abolishing the Congestion Charge Western Extension Zone (WEZ), which is expected to lead to a 12% increase in traffic.
And WEZ abolition could end up in court in an action threatened by members of pressure group Clean Air in London.
Boris Johnson has said "I fully support the principal objective of Clean Air in London which is to seek the improvement of the environment and public health". Well that's nice, although it's rather stretching the definition of "fully support". Clean Air in London has described Johnson's air quality strategy as "regressive, unfunded and inadequate".