The comment came ahead of a government-commissioned report to be unveiled next Monday on proposals to boost the flagging industrial competitiveness of Europe’s second largest economy.
The shift to a shorter work week was the flagship reform of the Socialist government that ruled France during a boom at the end of the 1990s. Many employers say it bloated labour costs and blunted their ability to compete in world markets.
Asked if it could make sense to revert to a 39-hour week, Mr Ayrault told Le Parisien newspaper: “Nothing’s taboo. I’m not dogmatic. The only thing that worries me is that France has broken down and we need to restart with the engine firing on all cylinders.”
Mr Ayrault, whose five-month-old government has been criticised for a string of communications gaffes, later clarified his remarks after business and union leaders seized on them as signalling a major policy shift.
“I said nothing was taboo. But this is simply not a cause the government advocates. There will be no rolling back on the 35-hour week because it is not the cause of our difficulties,” he said.
Laurence Parisot, head of the Medef employers federation, had earlier hailed Mr Ayrault’s initial comments as “excellent news” while trade union leaders were up in arms.
“If the government tries to take on the 35-hour week, it will run into us on the road,” the head of the large CFDT labour union, François Chereque, warned.
The shorter working week was intended to encourage employers to hire more staff by making higher overtime costs kick in after an employee had worked 35 hours in a given week.
Nicolas Sarkozy, the conservative president unseated in May by Socialist François Hollande, offered overtime tax breaks to lessen the impact of the measure but did not try to repeal it.