High Court Orders Manufacturers to Disclose Key Documents
Justice Constable rules that five car manufacturers must remove confidentiality restrictions from hundreds of documents.
On 25 July 2025, Mr Justice Constable at the High Court ruled that five car manufacturers must remove confidentiality restrictions from hundreds of documents related to alleged emissions cheating. The judge described the manufacturers’ confidentiality claims as "overenthusiastic" (Leigh Day).
The Ruling
The ruling requires the lead defendants — Mercedes, Nissan, Renault, Peugeot/Citroën and Ford — to disclose documents including test results, design documents, communications with regulators, and records of inter-manufacturer collaboration.
Justice Constable stated: "The importance of the public being able to understand the substance of the claims against the Lead Defendants outweighs any commercial confidentiality in that material" (Leigh Day).
Scale of the Litigation
The case involves approximately 1.8 million vehicle owners and is being co-led by law firms Leigh Day and Pogust Goodhead. The central question is whether diesel vehicles contained prohibited "defeat devices" designed to manipulate emissions test results.
Beyond the five lead defendants, additional manufacturers involved in the wider litigation include Vauxhall/Opel, Volkswagen/Porsche, Jaguar/Land Rover, BMW, FCA/Suzuki, Volvo, Hyundai-Kia, Toyota and Mazda (Leigh Day).
What This Means
The document disclosure is significant because the materials may contain evidence relevant to whether manufacturers knowingly circumvented emissions regulations. The ruling came ahead of the main trial, which opened on 6 October 2025 and was expected to last approximately three months.
A separate compensation trial is scheduled for spring 2026.
Sources
Think you might be eligible?
Use our free eligibility checker to find out if your diesel vehicle qualifies. No obligation, completely free.
Check your vehicle now
