Mums for Lungs calls for public transparency in Dieselgate hearing
10th July 2025
As part of our ongoing Dieselgate campaign, we attended the Pan-NOx Emissions Group Litigation hearing at the High Court this week. This is the next stage in our campaign to ensure public transparency and open justice in the upcoming £6 billion Dieselgate trial, scheduled for October.
Sam Hunter Jones (Client Earth), Sharon Erdman, Ruth Fitzharris (both Mums for Lungs) and Andrea Lee (Client Earth) outside the Royal Courts of Justice
The Dieselgate Litigation is one of the largest group actions to come before the English courts, with approximately 1.6 million car owners taking legal action against car manufacturers, including Mercedes-Benz, Ford, Nissan, Renault and Peugeot-Citroen, for allegedly using prohibited emissions "defeat devices" in their cars.
Earlier this year, we wrote an open letter to the High Court of Justice, signed by hundreds of individuals and over fifty organisations, requesting that documents in the litigation be made publicly available due to the high level of public interest in this case and the impact on human health.
Last month, we made an application to the Court, as did the environmental law organisation Client Earth. Our application asked the Court to remove the redactions from legal documents filed by auto manufacturers and to make the unredacted documents available to third parties on public interest grounds.
We believe that the heavily redacted materials include information relating to how the emissions control devices operate, such as the temperature, speed and torque thresholds at which they are alleged to artificially limit nitrogen oxides (NOx) emissions. As a result, the circumstances in which NOx emissions may be many times over the legal safety limits have been kept secret.
Our intervention seeks to bring an important public health issue to light, as there is a well-documented connection between nitrogen dioxide, the harmful component of NOx emissions, and adverse health impacts. Children are particularly vulnerable to the effects of exposure to air pollutants due to their higher respiratory rates and less developed respiratory systems. A recent report by the Centre for Research on Energy and Clean Air, commissioned by ClientEarth, concluded that in the UK, it is estimated that excess NOx emissions will have caused 22,000 premature deaths, 41,000 new cases of asthma in children, and cost £132 billion in economic burden between 2009 and 2040.
The outcome of the July hearing will significantly shape the October 2025 trial, which will determine whether the vehicles were fitted with illegal defeat devices. If the redactions are allowed to remain, it is alleged that much of this trial is likely to be conducted behind closed doors. We are urging the court to make the information publicly available, not just for public transparency and open justice but also to ensure these excessively polluting vehicles are finally cleaned up.
We are honoured to have been supported pro bono in this process by the amazing teams at Mishcon de Reya and Landmark Chambers - thank you Shazia, Frances, Destiny, Charlotte, Tim and Barney. We now await the judgment.