France froze sales of several Mercedes models on Friday, increasing the stakes in a dispute over Daimler's use of a European Union-banned refrigerant. 

R134a, a gas 1,400 times more potent than carbon dioxide and one of the leading causes of global-warming, was earlier banned by France due to safety concerns about the replacement compound, R1234yf. Germany, however, had allowed its use and re-certified the newly formed Mercedes automobiles despite warnings from the European Commission.

The government announced that it will maintain the sales ban on Mercedes A-Class, B-Class and CLA following Daimler's protest of the ban in court. Registrations "will remain forbidden in France as long as the company does not to conform to European regulations", stated the environmental ministry about Mercedes.

Daimler called the ban "absolutely incomprehensible", promising to take further legal action against France after Friday's fiasco.

France took initiative to outlaw sales of Mercedes vehicles developed since June 12 following Daimler's refusal to cease using R134a, an air-conditioning coolant banned from new vehicles since early 2013. The banned models constitute most of the German luxury carmaker's French units and around 2% of global distribution.