London High Court opens multibillion-pound diesel defeat devices case

A High Court trial opened on Monday in London in which about 1.6 million motorists are suing more than a dozen car manufacturers, alleging diesel vehicles made from 2009 onward were fitted with software that detected laboratory testing and altered emissions controls to pass official tests. The three-month hearing at the Royal Courts of Justice, before Lady Justice Cockerill, will focus on sample vehicles made by Mercedes-Benz, Renault, Nissan, Ford and Peugeot and Citroën; the judgment in that case will bind the wider group of claims against other manufacturers.

Claimants say the software, described in court documents as prohibited defeat devices, kept nitrogen oxide and other regulated pollutants within legal limits during test conditions but allowed higher emissions during normal driving, in breach of emissions rules and, they argue, consumers expectations. The action, led by law firms including Leigh Day, is the largest group claim in English legal history and has been valued at a minimum of about 6 billion pounds in court submissions. Lawyers for the claimants say budgets on both sides already exceed 300 million pounds.

Opening submissions for the claimants argued the...