Cars are pictured during morning rush hour at Schildhorn Street in a Berlin, Germany, February 22, 2018. REUTERS/Fabrizio Bensch

LEIPZIG (Reuters) - A German court might not reach a decision on Thursday after all on whether major cities can ban heavily polluting diesel cars, a ruling being closely watched by automakers and drivers of 15 million vehicles in Europe’s largest car market.

Judge Andreas Korbmacher told the court he was not sure whether the country’s highest federal administrative court would rule on Thursday after German states had appealed against bans imposed by local courts in Stuttgart and Duesseldorf.

Korbmacher suggested that the European Court of Justice might have to consider the issue of whether driving bans are permissible despite the lack of a national enabling framework.

There has been a global backlash against diesel-engine cars since Volkswagen VOWG_p.DE admitted in 2015 to cheating U.S. exhaust tests, meant to limit emissions of particulate matter and nitrogen oxide (NOx), known to cause respiratory disease.