Germany's Transport Ministry says it is backing Mercedes-Benz in its continuing dispute with the French government, which is refusing to certify the automaker's A, B, CLA and SL models in the row concerning its refrigerant choice.

Berlin's support for Mercedes will come as a boost to the manufacturer, which has launched a request to France's Council of State, the highest authority in the country, to issue a preliminary injunction to allow certification.

"Mercedes is [going] on their path and we are supporting their view," a German Transport Ministry spokesperson told just-auto from Berlin. "We are exchanging letters with the government of France on [the] interpretation of European legislation.

"The car market - [it] should be in their responsibility to bring on the market technically correct cars and [we] don't want the European Union to say use this or that cooling liquid if it does not work. It is a technical issue the car industry has to solve."

The German automaker uses the r134a refrigerant in its air-conditioning units - a chemical the European Union and France deem to emit excessively high pollution - but Mercedes claims the Brussels-mandated r1234yf variant can be highly flammable in certain conditions.

As well as Mercedes itself, the automaker's dealers are also hoping for a favourable response from the Council of State, as there are currently at least 5,000 blocked models not being delivered to customers.

The Conseil d'Etat says it acts as legal adviser to the French government as well as being the supreme administrative judge settling disputes relating to actions taken by Paris.