Picture: Stefan Wermuth / Reuters.

London - Lawyers for more than 50 000 British car owners kicked off a lawsuit against Volkswagen in London's High Court on Tuesday in a battle for compensation over a diesel emissions scandal that has engulfed Europe's largest carmaker since 2015.

The three-day hearing will determine whether the claims can be managed collectively under a Group Litigation Order (GLO) and will set a deadline for claimants to sign up to what lawyers say could become the largest group action in British legal history.

Volkswagen has said that about 11 million cars worldwide - and 1.2 million in the UK - were fitted with software that cheated diesel emissions tests designed to limit noxious car fumes and carbon dioxide (CO2) pollution.

VW agreed to pay up to $25 billion (R292bn) in the United States to settle claims from owners, environmental regulators, states and dealers and offered to buy back 500 000 polluting US vehicles.

But it has not reached a similar deal in Europe, where it faces billions of euros in claims from investors and customers in the worst business crisis of its 78-year history, dubbed "dieselgate".

British law firm Slater and Gordon, which represents more than 40 000 claimants in Britain, alleges that VW deceived people into buying cars that breached emissions regulations by installing "defeat devices", illegal engine management software designed to mask true pollution levels.

"The lawyers will argue that VW profited by lying about the compliance of their cars and betrayed the trust of consumers who thought they were purchasing a car that met emissions standards and which was fit to be sold to UK customers when this was not the case," the firm said in a statement.

The German company has offered to fix UK vehicles, and has said it broke no British laws and that drivers suffered no loss. German and British VW officials were not immediately available for further comment.

Owners not happy with the 'fix'

Slater and Gordon said it had surveyed more than 11 600 affected car owners who had agreed to the VW fix, which amounts to a software update of the engine management system. Over 50 percent of respondents regretted having it carried out, the lawyers said.

It said more than one in ten car owners told its survey that vehicles lost power at high speed, exposing them to danger after VW fixed their car. Drivers also reported poorer fuel efficiency and engine power and car juddering, it said.

"VW's only response has been to offer consumers in the UK a fix that our clients are telling us doesn't work," said Gareth Pope, a lawyer at Slater and Gordon.

Slater and Gordon is one of at least three law firms hoping to be granted the GLO. Lawyers have said that they expect the suit to come to trial next year if it is not settled.

If the GLO is granted, all past and present owners of affected VW, Audi, SEAT and Skoda cars can join the claim, regardless of whether they have had their cars fixed by VW.