The UK’s continuing diesel scandal
July 8th, 2026
Eleven years after Dieselgate, our updated analysis shows there are still over 7 million cars in the UK emitting thousands of tonnes of excess pollution every year.
Car manufacturers must be held to account.
Image: Crispin Hughes / Mums for Lungs
Excess diesel emissions
Our analysis of the latest government emissions data reveals that 7.1 million of the UK's 9.9 million diesel cars are Euro 5 and 6 models, emitting 48,700 tonnes of excess nitrogen oxides (NOx) annually above legal emission limits. Cars certified to these standards were shown to be using defeat devices which cheat emissions tests, after the 2015 Dieselgate scandal.
These 7.1 million diesel cars make up just under a quarter of the cars on UK roads, yet their excess emissions are responsible for almost 30 per cent of the total NOx emissions from road transport, including those from vans, buses and HGVs.
A whole generation of children has grown up breathing these excess emissions, with 30,000 cases of childhood asthma, 800,000 days of sick leave and a £96bn cost to the economy estimated to be attributed to this.
The group claim trial
Image: Ron Fassbender
Last year, as the scale of these excess emissions became apparent, we took our fight to the courts. We protested outside the High Court as the Pan-NOx Emissions Group Litigation - the biggest group claim ever to reach UK courts - was due to get underway.
Car manufacturers wanted to keep details of the case confidential, so we applied to the Court alongside ClientEarth and the Scottish NOx Emissions Steering Group for access to certain documents, to ensure public transparency. We won - the High Court ordered manufacturers to release unredacted documents ahead of the trial.
On the first day of the October 2025 trial, we returned to the Royal Courts of Justice and wrote jointly with ClientEarth and Asthma and Lung UK to the Secretary of State for Transport, calling on the government to ensure action is taken to remove excessively polluting cars from our roads.
This updated data shows that the problem has not gone away. The government needs to act and take these cars off our roads.