Crowds poured into the streets in major cities across France to protest changes that President Emmanuel Macron wants to make to the country's labor code, waving flares and brandishing signs with sarcastic slogans such as "slackers of all nations unite."The show of opposition, led by the far-left union CGT, is seen as the first major test for the recently elected leader.At the edges of the demonstration in Paris, there were clashes between black-clad protesters and police. According to Reuters, "police fired water canons and could be seen dragging several demonstrators behind their lines."The mobilization are focused on proposed changes to France's 3,500-page labor code that were introduced last month.Parliament has given Macron the power to push through the changes by executive order, and Reuters reports that "the government plans to adopt the new measures ... on Sept. 22."Macron "wants to give companies more leeway in firing and hiring to spur job creation," NPR's Eleanor Beardsley reports from Paris. "His changes will also allow workers and bosses to negotiate their own company rules."But CGT says the overhaul "will erode hard won worker rights and create precarious jobs," Eleanor adds.Macron is trying to pull off changes that other presidents could not. As Eleanor has reported: "Previous French presidents have abandoned attempts to loosen the country's rigid labor market in the face of weeks and sometimes months of strikes and street protests."The president stoked the controversy Friday, according to The Associated Press, by saying that "I am fully determined and I won't cede any ground, not to slackers, nor cynics, nor hardliners."The AP says Macron later tried to clarify that the "slackers" he was referring to were previous politicians who were unable to enact changes. But the phrase has become a rallying cry for demonstrators, with some brandishing signs that say things such as "I am a slacker."Alain Cure, an elementary school principal demonstrating in Paris, told The New York Times that it is "important to show that we, as union workers, are united."However, it's worth noting that France's unions are divided on the overhaul. As Reuters reports, "two other unions, including the largest, the CFDT, declined to join the protests."France has an unemployment rate of over 9 percent. And public opinion on Macron's changes also is divided, according to the wire service: