A landmark ruling by the German Federal Administrative Court in Leipzig on 27 February 2018 declared that the cities of Stuttgart and Düsseldorf were allowed to legally prohibited older, more polluting diesel vehicles from driving in zones worst affected by pollution, rejecting appeals made by German states against the bans imposed by the two cities' local courts. The case was strongly influenced by the ongoing Volkswagen emissions scandal (also known as Dieselgate), which in 2015 revealed that many Volkswagen diesel engines were deceptively tested and marketed as much cleaner than they were. The decision was predicted to set a precedent for other places in the country and in Europe. Indeed, the ruling triggered a wave of dozens of local diesel restrictions, brought about by Environmental Action Germany (DUH) suing city authorities and winning legal challenges across Germany. While some groups and parties such as the AfD again tried to overturn them, others such as the Greens advocated for a national phaseout of diesel cars by 2030. On 13 December 2018, the European Court of Justice overturned a 2016 European Commission relaxation of car NOx emission limits to 168 mg/km, which the Court declared illegal. This allowed the cities of Brussels, Madrid and Paris, who had filed the complaint, to proceed with their plans to also reject Euro 6 diesel vehicles from their urban centres, based on the original 80 mg/km limit set by EU law.