France's highest Court has temporarily suspended the refusal of the Transport Ministry to grant Mercedes-Benz certification of its A, B, CLA and SL models with these now due to be registered starting tomorrow (29 August).

The Conseil d'Etat or Council of State made its ruling against a backdrop of claim and counter claim between the German automaker, the French authorities and the European Commission (EC), concerning Mercedes' use of its preferred r134a refrigerant as opposed to the r1234yf alternative.

The judgement from the Paris Court noted there was: "A serious doubt on the legality of the [six month EC-mandated] safeguard clause" and that the vehicles would not "seriously harm the environment."

Mercedes has continued to maintain the Brussels-recommended r1234yf presents a fire risk in certain conditions, but Paris and the EC insist the German preference for r134a is highly polluting.

For its part the French Transport Ministry noted the temporary ruling and said it would deliver the identification codes for the vehicles concerned by 29 August.

"The registration of these vehicles is therefore temporarily authorised on national territory, until the definitive decision by the Council of State," said a Ministry statement. 

The dispute between the parties has moved from a purely automotive difference of opinion to a highly politicised spat, with Germany firmly backing Mercedes-Benz in its use of the r134a refrigerant.

Germany's Transport Ministry has supported the automaker, while a final report from the country's road safety authority, the Kraftfahrt-Bundesamt, is expected later this year.