Sadiq Khan’s office tried to discredit and “silence” scientists who found that his ultra-low emissions zone (Ulez) policy had little impact on pollution, The Telegraph can disclose.

In private emails seen by The Telegraph, Shirley Rodrigues, the London Mayor’s deputy for environment and energy, told Prof Frank Kelly she was “really disappointed” that Imperial College had publicised findings questioning the effectiveness of Ulez.

Prof Kelly, a director of Imperial’s Environmental Research Group, which has been paid more than £800,000 by Mr Khan’s office since 2021, agreed to issue a statement – partly written by Ms Rodrigues – saying Ulez had helped to “dramatically reduce air pollution”.

London Conservatives said the correspondence revealed an “alarmingly cosy relationship” between the Mayor’s office and the scientists it was funding, as well as a desire to “silence scientists who question the effectiveness of Khan’s policies”.

Prof Kelly’s colleagues said they stood by their research “100 per cent”, but The Telegraph understands that the fallout has had a chilling effect, leaving them unwilling to publish further work on the subject.

The study from the Department of Civil and Environmental Engineering, published in the journal Environmental Research Letters in 2021, found that the introduction of Ulez in 2019 cut nitrogen dioxide by less than three per cent and had insignificant effects on ozone and particulate matter.

Peter Fortune, the Conservative London Assembly Member for Bexley and Bromley, two of the boroughs challenging the Ulez expansion, said: “It is unacceptable that Sadiq Khan and his deputy conspired to silence legitimate research because it would damage the Mayor’s reputation and credibility.

“Sadiq Khan has claimed he is just following the science, yet he has been using scientific advisors to protect his own interests. Science relies on open, transparent debate.”

Imperial’s Environmental Research Group has been paid at least £802,958 by Mr Khan’s office since 2021, including a payment of £45,958 for a report on the “future health benefits of mayoral air quality policies” which has been widely cited by the Mayor despite not being peer reviewed.

Cllr Colin Smith, the leader of Bromley Council said: “When academics are paid for their research, it quite reasonably leads to questions being asked about the outcomes sought by those commissioning the work.

“Indeed, as long ago as last autumn we directly challenged Imperial as to their methodology and the conclusions of some of their research ourselves, and the revelation of these emails now serves to seriously heighten those concerns.”

Emails released under Freedom of Information requests show that Ms Rodrigues wrote to Prof Kelly on Nov 16 2021, complaining that Sky News, The Times and The Mail were running a “misleading” Ulez study that had been press released by Imperial College.

Ms Rodrigues thanked Prof Kelly’s team for trying to stop Imperial’s press office from releasing the research and said that she was “deeply concerned” about the damage the study was doing to credibility of the Mayor’s office and Ulez.

She added: “Is there anything you can do or advise to help us set the record straight? I would really appreciate any support.”

Prof Kelly replied, saying he was “totally dismayed” and was “pursuing options internally to offset this”. He said he would be “very happy to provide the Greater London Authority with support required as you move to mitigate the damage”.

Prof Kelly sent a statement to Ms Rodrigues to check, which initially said actions by the Mayor were “collectively providing a major benefit to the city”. She replied, crossing out the word “collectively” and adding that the Mayor’s schemes “have dramatically reduced air pollution in London”.

Cllr Paul Osborn, the leader of Harrow Council, which is resisting the Ulez expansion, said: “These dodgy emails raise important questions about the scientific basis for extending the Ulez. I have long believed that this expansion will have a very limited impact on air pollution but comes at a massive cost to the poorest and most vulnerable motorists.”

The emails also show that, on Feb 14 this year, the Greater London Authority (GLA) asked Prof Kelly to complain about a Telegraph article reporting on the uncertainty of air pollution death figures widely cited by Mr Khan, based on Prof Kelly’s research.

The GLA offered to set up a “friendly interview” for him with “very supportive” David Lammy, the Labour MP for Tottenham. 

At the time, Prof Kelly warned that “Imperial’s press office is not keen for us to put a direct contradiction to the Telegraph article”, but said that “as always, I’m happy to fight back”. He also asked the Mayor’s office to provide him with “a form of words” with which he could challenge the article.

Cllr Baroness O’Neill of Bexley added: “These findings confirm everything we knew, in that the data used to build the case for extending Ulez was flawed. Extending Ulez has always been more about the Mayor of London’s drive for income generation than improving air quality for Bexley residents.”

On April 17 , Prof Kelly admitted on the Evening Standard’s The Leader podcast that his research, paid for by the Mayor, would give Mr Khan “useful ammunition” to promote his Ulez expansion.

On June 6 , Prof Kelly wrote to Rishi Sunak, the Prime Minister, alleging that politicians were “not believing the science” on air pollution. Six of the signatories were part of the Imperial team, but they did not disclose that they were being funded by the Mayor’s office.

A spokesman for Mr Khan said: “It is right – and standard practice across government – that we commission experts to carry out research to inform the work we do.

“Frank Kelly and the Environmental Research Group at Imperial are some of the world-leading academic institutions looking at air quality. It is normal and proper to work with these experts to ensure our policies are as effective as possible at dealing with issues such as the high number of deaths – up to 4,000 a year – linked to toxic air in London every year.

“The Ulez analysis from the engineering department at Imperial only paints a partial picture, not accounting for the full lifetime impact of the scheme and only focusing on its immediate impact around its launch. It is commonplace for academic experts to disagree with how other academic studies are interpreted, as was the case here.”

The Telegraph has approached Imperial College for comment.

(Source: The Telegraph)