France's boss of bosses warned voters on Tuesday against backing the far-right in regional elections this weekend in a rare move which he said was justified because the National Front's economic agenda was not a "responsible" one.
Pierre Gattaz, head of France's employers' group Medef, made his comments with polls showing a rise in the FN's ratings this year against a background of a migrant crisis in Europe and the Islamic State attacks that killed 130 people in Paris.
The anti-Europe, anti-euro FN's economic agenda is "exactly the opposite of what we need to kickstart economic growth in this country," Gattaz told Le Parisien daily in an interview.
While the Medef employers' group regularly lobbies the government on its economic policies, it usually stays clear of intervening in an election or telling voters who to back.
On Monday, the northern region's main daily La Voix du Nord also took the unusual step of urging readers not to vote for the FN, showing growing concern at polls which see FN victories as increasingly likely in two or three of 13 mainland regions.
The FN, which has seen its popularity rise since 2011 as Marine Le Pen took over from her father and strived to soften its image, won eleven municipalities in 2014 but currently rules no regional council.
Surveys show Le Pen topping the vote in the first round on Sunday in the northern Nord-Pas-de-Calais region and her niece Marion Marechal-Le Pen doing the same in southeast France.
While the second round is harder to predict, surveys see both winning in the second round on Dec.13.
The usually low-key election for regional administrations is this time a key test for France's main parties as they gear up for the 2017 presidential vote.
Winning in one or two big constituencies could be a useful stepping stone for the FN in 2017, one that might convince voters it has the experience to rule the country.
President Francois Hollande's Socialists, who currently rule most regions, are set for defeat, and ex-president Nicolas Sarkozy's The Republicans are expecting a second victory this year after winning in another local election in March.
But the latest polls show the Socialists' defeat could be smaller than they feared and Sarkozy's wins not as big as he hoped for, partly because of the impact of the Paris attacks on a complex election.