"The traffic light should urgently remedy this and adapt civil procedural law to the new reality of these mass lawsuits with which specialized law firms are heaping the courts through more flexible regulations," demanded Rebehn. "Law firms specializing in diesel cases are already campaigning aggressively for new mandates, so that the number of cases in many courts is likely to continue to rise significantly." How large the predicted new wave of lawsuits will also depend on the Federal Court of Justice, which will soon further specify the European requirements in a decision.

The higher regional courts and many regional courts in Germany are already under heavy strain from diesel lawsuits, said Rebehn. The 24 higher regional courts alone recorded more than 28,500 proceedings last year. Five years earlier, the number of diesel cases in the court of appeal was still around 11,500.

The European Court of Justice (ECJ) ruled on Tuesday that car buyers can claim damages from the manufacturer if they have suffered damage due to an illegal defeat device for exhaust gas cleaning installed in the vehicle.