“He agrees that class struggle is the watchword of history, and that workers are necessarily in combat against bosses,” said René Mouriaux, a leading historian of the French union movement. In Mr. Martinez’s view, he added, between bosses and workers “there can be compromises, but no definitive agreements.”
Three weeks ago, Mr. Martinez’s workers went on strike to block the printing of France’s national newspapers for a day after newspapers refused to publish a commentary he had written. The Communist newspaper L’Humanité was the only one to print it.
“Philippe Martinez, the man who wants to bring France to its knees,” read a recent headline in the right-leaning newspaper Le Figaro. An article in the left-center newspaper Le Monde called him “the Lider Maximo of the protest movement.”
On Friday, Mr. Martinez angrily denied that the protest had been connected to the violence at the march through Paris, which left the Boulevard du Montparnasse, a main artery of the city’s Left Bank, looking like a war zone.
“The hooligans are there to discredit our movement,” he told journalists in the courtyard of the Labor Ministry, vowing to continue the marches until the government gives up its labor law.
But despite Mr. Martinez’s belated disavowals, violence, including serious injuries, has been a constant feature of his union’s protests over the past few months.
Paris’s police prefect has released photos of union members ripping up paving stones to be used as projectiles. Mr. Martinez said they had simply been defending themselves.
Shocked by the smashed windows at the children’s hospital, Mr. Hollande said a ban on future demonstrations was possible, provoking outrage among some members his own Socialist Party.
“There’s no reason for us now to back down from our days of mobilization,” Mr. Martinez told reporters on Friday after a fruitless meeting with the labor minister to end the standoff. “For three months, the government has been counting on us to lose steam. It’s been a bad bet.”
Mr. Hollande’s government is equally unlikely to back down. It is pinning its hopes of denting France’s chronically high unemployment on a law that would only slightly relax negotiating conditions between workers and management.
The change is considered mild by most economists, but has been deemed hopelessly pro-capitalist by Mr. Martinez’s union and even by members of Mr. Hollande’s party.
Months of protests have weakened the proposed law, and it no longer includes a mechanism to cap payouts to fired workers. The law would also define more precisely how companies could lay off workers — currently an arduous process in a country where workers are highly protected.
But the part of the proposal that most infuriates C.G.T. and a few other unions would allow labor agreements negotiated by individual companies — over such issues as hours worked, paid holidays and bonuses — to take precedence over agreements negotiated at the occupational sector level.
That change would weaken the power of unions such as C.G.T., and it has made Mr. Martinez see red. “You’ve got to respect the hierarchy of norms,” he told reporters on Friday, while leaving the door slightly open to possible exceptions.
Yet with each new burst of violence in the streets, the government is increasingly dismissive of Mr. Martinez and his motives. Some government officials say that the violence will backfire and put the French on the side of the labor law, and that Mr. Martinez is using the violence to shore up his base.
If so, the union leader is doing a good job. France has among the lowest rates of unionization in Europe, and C.G.T., which represents train workers, metalworkers, public sector workers, miners and others, has been losing members for years. Between 1975 and 1993, it lost nearly two-thirds of its members, and now stands at about 686,000.
Today it is made up of mainly hard-core militants, analysts say. The old-fashioned language of class struggle was much in evidence among the crowds at Tuesday’s march, underscoring how many of France’s contemporary struggles are rooted in both the language and facts of its history.
“I Am in the Class Struggle” was a sticker sported by many protesters. “Work Is a Crime Against Humanity,” read another. “Victory in Chaos,” someone had scrawled on a building. “The Struggle Is About Class Against Class,” read one billboard.
Mr. Martinez moves easily among these views. His father fought in the Spanish Civil War in the International Brigades against the fascists, and his mother was a housekeeper.
C.G.T. was founded in 1895, and its “explicit aim was to bring down the state,” said another historian of French labor, Nick Parsons of Cardiff University in Wales. “It still has that anticapitalist orientation.”
“This is a guy who was brought up in that sort of atmosphere,” Dr. Parsons added. “He’s imbued with that history and culture.”
Mr. Martinez has shown a willingness to compromise in negotiations as a metalworker representative in preceding decades, Dr. Parsons noted. But that side is not evident now, with polls showing that most French people are still opposed to the labor law.
The class struggle continues.
“It shouldn’t be called the ‘law on work,’ but the ‘social dumping law,’” Mr. Martinez yelled during a recent speech at a factory in southern France. “We’re not close to giving up. The stakes are high — for today’s workers, for the young, for our country.”