Volkswagen installed unlawful software to cheat emissions tests in thousands of cars that were sold in Britain, a High Court judge has ruled.

In the first significant ruling on mass litigation brought in England and Wales over the 'dieselgate' emissions scandal, Mr Justice Waksman backed assertions made by 86,000 motorists who bought Volkswagen cars and diesel vehicles made by Volkswagen but branded Audi, Seat and Skoda, The Times reported.

Lawyers for the motorists had argued the automaker cheated European emissions standards, which were designed "to save lives", by installing unlawful "defeat devices" in its diesel vehicles. This meant that the vehicles were emitting up to 40 times the legal limit of nitrogen dioxide.

In a judgment delivered remotely, Justice Waksman ruled that "the software function in issue in this case is indeed a defeat device" under EU regulations. He said he was "far from alone in this conclusion", referring to "numerous courts and other bodies in various other jurisdictions (which) agree that the software function here is a defeat device".

Lawyers for the claimants have brought the action for compensation in what legal experts have predicted could be the largest consumer action in English legal history, the newspaper noted.

Gareth Pope of the law firm Slater and Gordon, which represents about 70,000 of the claimants, described the ruling to The Times as "damning". He said that it "confirms what our clients have known for a long time, but which VW has refused to accept: namely that Volkswagen fitted defeat devices into millions of vehicles in the UK in order to cheat emissions tests".

He pointed to the judge's description of Volkswagen's defence as "highly flawed", "hopeless" and "absurd".

Pope said the case "exposed Volkswagen's approach to this litigation and its customers — refusing to admit wrongdoing and compensate its customers in favour of running drawn out and pointless litigation.

"The court's conclusion that the existence of software was a fundamental subversion of tests designed to limit pollution and make our air safe to breathe exposes Volkswagen's disregard for EU emissions regulations and public health in pursuit of profit and market dominance.

"Volkswagen's utter failure to convince the court of the merits of its case means that now is surely time for it to settle these claims and put this shameful episode behind it."

Bozena Michalowska-Howells, a lawyer with Leigh Day, which also represents claimants, told The Times: "Many of our clients have been horrified to find out that they had been driving vehicles which were much more harmful to the environment than they were led to believe."

She called on Volkswagen to accept the decision and to "do the right thing and put their customers first by entering into settlement negotiations so that our clients are not forced to drag Volkswagen through the courts and be faced with further years of litigation to determine their losses".

The English litigation was launched in 2016, but reached what lawyers described as "a decisive court battle" at a preliminary hearing in December when the High Court was asked to decide whether software installed in Volkswagen cars was a "defeat device" under EU regulations.

Volkswagen's emissions crisis