How millions of car owners could be owed compensation after landmark legal battle
Millions of drivers could soon be entitled to compensation as a major legal battle begins in the Supreme Court. Dozens of popular car manufacturers are allegedly violating rules on emissions as vehicle owners file lawsuits against them.
Five major automakers have been accused in court of cheating on emissions tests, and many more have the potential to face a similar challenge depending on the outcome of the fight.
The five companies involved: Mercedes, Ford, Peugeot/Citroën, Renault and Nissan, all deny the accusations.
The hearing marks a significant development in the ongoing ‘dieselgate’ scandal, with the potential to affect 1.6 million vehicle owners in what lawyers describe as the largest class action in English and Welsh legal history.
Companies are facing allegations that they used software that allowed their vehicles to reduce harmful gas emissions under test conditions.
Five companies were selected by the court as the primary defendants to be tried first. Depending on the outcome of the case, nine other automakers could face similar claims.
These are: Opel and Vauxhall, Volkswagen and Porsche, Jaguar Land Rover, BMW, FCA and Suzuki, Volvo, Hyundai/Kia, Toyota and Mazda.
Here’s everything you need to know:
When did the problem start?
The action follows the “dieselgate” scandal, which first emerged in September 2015 when the US Environmental Protection Agency accused Volkswagen of installing software designed to manipulate nitrogen oxide emissions into its diesel vehicles.
The Supreme Court confirmed in 2020 that Volkswagen had breached EU emissions testing requirements by using these devices. The carmaker later filed a £193 million class action lawsuit against 91,000 drivers in the UK.
It has so far paid out £27.8bn worldwide, mostly in the US.
Starting Monday, the Supreme Court will determine whether systems in diesel cars from five other manufacturers are similarly designed to circumvent clean air laws.
These companies face allegations that defeat devices allow cars to set test scenarios, causing them to run at lower power and record artificially low nitrogen oxide emissions.
Lawyers for the affected drivers argue that their clients were deceived about the environmental impact of the vehicles and that they continue to emit dangerous levels of pollution on the roads. A decision is not expected until summer 2026.
Will there be compensation?
If the court rules against the automakers, a new hearing to determine compensation payments to those affected is likely to be held in Fall 2026.
If the court finds that the sample vehicles considered at trial contained defeat devices, the plaintiffs will argue that this gives rise to claims of breach of legal duty and contractual obligations.
They will also argue that, based on the jurisprudence of the Court of Justice of the EU (CJEU), consumers are entitled to compensation for vehicles containing defeat devices.
Although the exact amount that may be owed in each case will be subject to a lengthy legal process, Leigh Day estimates it could be in the “thousands”. The law firm were joint attorneys in the original diesel emissions group case and are one of 22 law firms representing drivers in the Supreme Court.
Leigh Day said it currently only accepts claims relating to vehicles manufactured by Volvo and that these claims cannot be heard as part of ongoing litigation but could be heard in subsequent legal proceedings.
The deadline to submit a claim to most other law firms has also now passed, but those who think they may be affected are advised to monitor proceedings for any updates that may affect them.
Speaking ahead of the hearing, Martyn Day, senior partner at Leigh Day, said: “Ten years after the Dieselgate scandal first emerged, 1.6 million UK motorists now have the chance to determine at the hearing whether their vehicles contain technology designed to cheat emissions tests.
“14 of the largest car manufacturers operating in the UK are facing these allegations, which if proven would represent one of the most egregious breaches of corporate trust in modern times.
“This could also mean that people in the UK are breathing in far more harmful emissions from these vehicles than they are told, potentially putting the health of millions more at risk.”
