The leader of City Hall Conservatives has leveled accusations against London Mayor Sadiq Khan, claiming that he collaborated to suppress research related to the Ultra Low

Emission Zone (Ulez).

Email correspondence has revealed that deputy mayor for environment and energy, Shirley Rodrigues, twice approached an air quality expert in an attempt to counter research that questioned the effectiveness of the pollution-vehicle charge.

The air quality expert, Professor Frank Kelly, and his science team from Imperial College London, have received nearly £1 million in funding from Mayor Khan's office.

In response, Mayor Khan dismissed claims that the funding influenced Professor Kelly's work.

The expansion of Ulez has sparked controversy, with the Conservatives attributing their victory in last month's Uxbridge and South Ruislip by-election to public dissatisfaction with the policy. This election filled the seat left vacant by former prime minister Boris Johnson.

The Ulez expansion, which withstood legal challenges from five councils, entails drivers in outer London paying £12.50 per day starting from August 29 if their vehicles fail to meet emissions standards.

Emails between Ms. Rodrigues and Prof. Kelly, obtained through a Freedom of Information request by the Conservative Party, have revealed concerns voiced by Ms. Rodrigues regarding a study published by fellow Imperial academics. The study suggested that the central London Ulez had a limited effect on air pollution, showing that harmful nitrogen dioxide concentrations were reduced by less than 3% in inner London nine months after the zone's expansion.

Ms. Rodrigues expressed her concerns in the emails, asking Prof. Kelly for advice on addressing the issue. Prof. Kelly agreed to issue a statement supporting the mayor's office and the Ulez, with Ms. Rodrigues modifying the statement for clarity.

Neil Garrett, leader of City Hall Conservatives, argued that the emails suggested an effort to suppress research not aligned with the mayor's policy. He expressed concerns about relying on the science and suggested that the focus should extend beyond the Ulez.

A spokesperson for Mayor Khan emphasized that commissioning experts for research was standard practice and that disagreements between academic studies were common.

The spokesperson also stated that the Ulez analysis conducted by Imperial's engineering department did not account for the full impact of the scheme and only considered its immediate effects upon launch. The mayor's own report indicated a 21% reduction in NO2 concentrations in inner London due to the Ulez. Photo by Shadowssettle, Wikimedia commons.