The advertising watchdog launched a probe earlier this year after hundreds of people complained the Mayor’s transport authority exaggerated the extent to which the ultra-low emission zone would improve the capital’s air quality in paid for newspaper and radio features.
The critical findings by the Advertising Standards Authority (ASA) is expected to criticise Transport for London, for “misleading” claims about the expansion of Ulez reducing levels of poisonous nitrogen dioxide (NO2) particles.
The classified report was leaked to The Sunday Telegraph after being sent to interested parties before any potential amendments, ratification and publication.
One campaigner who complained to the watchdog about the adverts said the nine-page document showed Mr Khan “lied” about the impact Ulez would have on pollution.
The advertising watchdog’s recommendations say two complaints about two radio and one newspaper adverts are to be upheld.
A total of 578 people contacted the ASA to “challenge” TfL to prove the claims in the adverts, which were broadcast and published between January and June this year. The adverts claimed Ulez had “seen almost a halving of levels of nitrogen dioxide”, “most air pollution related deaths actually occur in outer London” and that Ulez had made a signicant difference by helping to reduce harmful nitrogen dioxide pollution by nearly half in Central London.
The ASA found two adverts were “misleading” because they “did not clarify” claims NO2 levels had “reduced by nearly half” as a result of Ulez and were based on “estimates or modelled scenarios” and not “actual figures”.
The second complaint expected to be upheld found an advertisement that claimed deaths from pollution were higher in outer London failed to make clear that that area had already been covered by Ulez.
A TfL spokesman said: “The science is absolutely clear about the significant harm of air pollution on people’s health and that estimated premature deaths from air pollution are higher in outer London than in inner London. We are confident that the advertisement is accurate.”