Major automakers are on trial over fraud claims over ‘dieselgate’ emissions

A historic legal battle will begin at the Supreme Court on Monday as five major carmakers are accused of cheating on emissions tests.

The trial marks a major development in the ongoing ‘dieselgate’ scandal, which could impact 1.6 million car owners in what lawyers are describing as the largest class action in English and Welsh legal history.

The companies are accused of using software that allowed their cars to reduce harmful gas emissions under test conditions.

The five carmakers involved are Mercedes, Ford, Peugeot/Citroen, Renault and Nissan, all of which deny the allegations. 968,813 claims have been filed with these companies on behalf of 846,466 claimants.

The five companies were chosen by the court as main 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.

The ‘dieselgate’ scandal dates back to September 2015, when Volkswagen was accused by the US Environmental Protection Agency of installing software on diesel cars to reduce nitrogen oxide emissions.

Known as “defeat devices,” the Supreme Court ruled in 2020 that Volkswagen had used the software, breaching European Union emissions testing requirements.

The carmaker settled a class action out of court and paid £193 million to 91,000 British drivers. So far the company has paid out more than £27.8 billion over the scandal, mainly in the US.

From Monday, the Supreme Court will decide whether the systems installed in diesel cars by the five carmakers were similarly designed to circumvent clean air laws.

They are facing accusations that defeat devices were used to get a car identified when it was in a test scenario. This would cause the engine to run at a lower power level, meaning lower nitrogen oxide values ​​were recorded.

Lawyers representing motorists claim their clients have been misled about the environmental impact of the vehicles, and that the cars’ continued presence on the roads means dangerous levels of pollution continue to be emitted.

A ruling is not expected until the summer of 2026. If the court rules against the car manufacturers, a new trial will likely take place in the autumn of 2026 to determine compensation payments to those affected.

Martyn Day of Leigh Day, one of 22 law firms representing drivers, said: “A decade after the Dieselgate scandal first came to light, 1.6 million British motorists will now have the chance to determine at trial whether their vehicles contain technology designed to cheat emissions tests.”

If the allegations against the car companies are upheld by the court, it would demonstrate “one of the most egregious breaches of corporate trust in modern times,” he added.

“It would also mean that people across the UK have inhaled far more harmful emissions from these vehicles than they were told, potentially putting the health of millions of people at risk.”

Those who took legal action purchased, leased or otherwise acquired a diesel vehicle from one of the companies, most of whom lived in England and Wales, but some elsewhere in the UK.

Mercedes owner Adam Kamenetzky said: “If these allegations are true, regulators, politicians and the public have been deceived by manufacturers who, it is alleged, profit from their sales of diesel cars while flouting clean air laws and measures like Ulez, which aim to improve public health.”

The companies involved in the case deny the claims.