Dear Sir Robert

Re: Use of statistics on the Ultra Low Emissions Zone

I am writing to raise concerns about the claims made by the Mayor of London, Sadiq Khan, regarding the levels of compliance of vehicles in outer London with the Ultra Low Emission Zone that is due to expand in August.

Sadiq Khan claims that 9 in 10 cars seen driving in outer London now meet the Ultra Low Emission Zone standards, but these figures are misleading. Initially, the figure was 85% of vehicles were compliant, but TfL and the Mayor have now increased this claim.

Furthermore, at the London Assembly on the 23rd March, the Mayor claimed that “new data shows that nine out of 10 of those households in outer London who have a car are compliant, so very few have non-compliant cars in outer London”. This is a significant misrepresentation of TfL’s own claims.

Liberal Democrat analysis has suggested that up to a quarter of vehicles registered in outer London could be non-compliant with ULEZ, while TfL’s own documents suggest that outer London compliance is “62% to 72%”.

It is irresponsible for the Mayor of London to use figures to justify a policy when those figures do not seem to be backed up by the evidence. Misuse, or in this case rejection, of statistics by politicians can lead to pressure for policies that are not supported by the data.

The Government has confirmed that TfL has a data sharing agreement in place with the DVLA to provide information about UK registered vehicles. The Mayor should therefore be able to provide accurate information regarding the numbers of vehicles registered in the new ULEZ.

I therefore ask that you investigate the Mayor of London and offer your guidance on whether or not it would be appropriate for him to publish those figures.

I look forward to your response on this matter.

Yours sincerely


MP for Twickenham


Related Links

Response from Sir Robert Chote to Munira Wilson MP – ULEZ statistics