A top Mitsubishi executive has criticised France’s industrial recovery minister using language that can only be described as ‘harsh’. Jean-Claud Debard, head of Mitsubishi France branded Arnaud Montebourg a “retard” for “ruining the life of motorists” with excessive restrictions and high taxes.

Debard, head of Mitsubishi France, called Mr Montebourg a “retard” for punishing motorists who bought high-emissions vehicles.

Unsurprisingly, Debard has since resigned “for personal reasons”.

Jean-Claud Debard’s frustration bubbled over after the French minister’s outspoken drive to convince French motorists to buy French, rather than ‘foreign’ vehicles. The politician has offered subsidies for those who bought eco-friendly cars and given penalties for those who splash out on high-emissions vehicles.

Debard, whose company happened to be launching a new SUV in southern France, appeared to let his frustration get the better of him, saying: “This mental case, this retard, increases ecological taxes, reduces the speed motorists can go on Paris’ ring road and ruins the life of motorists from all social origins and all suffer as a result of him,” La Provence newspaper reported.

“He is stupid and understands nothing, you can quote me on that,” he continued.

This isn’t the first time Debard and Montebourg have bumped heads. The Mitsubishi chief has challenged the French minister in the past, and claimed the last time he insulted the politician on television he was hit by a tax investigation.

Mr. Montebourg, Debard claims, does not care about the car sector, ignoring the fact that the car sector represented “25 per cent of Freance’s turnover and 10 per cent of the jobs in our country.”

The backdrop to this falling out is France’s ailing car sector, which suffers from falling demand and high labour costs. Peugeot recently announced 8,000 job cuts and has closed a plant, putting thousands of jobs at risk. On Wednesday, the French government promised PSA Peugeot Citroen up to seven billion euros (£4.4b) in bank guarantees in return for reducing redundancies.