More than 600,000 protesters have taken part in rallies and marches across France, according to France's interior ministry, with five unions joining a day of action demanding more money for wages and public services.
The left-wing CGT union put the number of people taking part in Thursday's mobilisation at 1.57 million and hailed the figure as "a level unmatched" since 2023, citing big protests in Paris, Marseille, Bordeaux and Lille.
As darkness fell in Paris, Prime Minister Sébastien Lecornu said he would convene a "social conference" with unions and employers next Monday.
The wave of protests began in September over poor conditions and resources at lycées (high schools), before spreading to universities, workers and a revived "yellow-vest" movement against high prices.
The unions had vowed to take the co-ordinated move against the government "to the next level", and CGT chief Sophie Binet had said their message was that "the only thing that will bring this mobilisation to a halt is responding to our demands".
Interior Minister Laurent Nuñez had earlier deployed 70,000 police, vowing "an extremely firm response" to any potential outbreaks of violence.
Some unrest was reported in several cities.
A car was set alight near the Gallieni bridge over the Rhône river in Lyon, as hundreds of activists from the radical left-wing "black bloc" clashed with police.
Clashes were also reported in the north-western city of Rennes, where the local prefect said a "hostile group of masked individuals" had gathered in front of the main union march. Tear gas was used to clear a square in the south-western city of Bordeaux and a teenager was hurt in a stabbing involving a student at a high-school blockade in the Seine-Saint-Denis suburb of northern Paris.
But the trouble was not on the scale seen during the last big day of protests, on Saturday 17 October, when more than 2,000 stores were looted and historic buildings set on fire.
The provisional numbers reported on Thursday were higher than on 17 October, considered the biggest day of rallies until now when the interior ministry said 550,000 people had turned out and the unions counted 800,000.
Earlier on Thursday the leader of the CFDT union, Marylise Léon, said she would be happy if the protests matched that earlier level.
The head of the CFDT complained that it was not just the minimum wage that needed to increase. "We are asking for a net increase of €100 a month," Marylise Léon explained.
The government has sought to appease public anger over rising prices, bringing down the cost of fuel by releasing 10 million barrels of diesel from strategic reserves. Ministers have also promised school students to reform the unpopular Parcoursup university admissions platform and eventually replace it by 2028.
The prime minister said early on Thursday evening that Monday's "social conference" with unions and employers would seek to "provide answers to questions surrounding purchasing power and wages".
However, the government by its own admission has little room to manoeuvre, as it looks to make tens of billions of euros in savings, in a bid to cut the budget deficit to 5% of GDP.
The education ministry said that 16% of teachers had gone on strike on Thursday, and the unions said disruption had affected more than one in four lycées, which cater for 15-18 year-olds, as well as the vast majority of universities.
"Now it's not only about [investing in] public services in education and higher education, it's about all of the public services in France," the vice-president of the Unef student union, Alice De Brito, told the BBC.
Meanwhile, a revived gilets jaunes (yellow-vest) movement that staged a revolt against the high cost of living several years ago has called for further blockades and protests on Friday and Saturday too.