Protesting students and trade unionists took to the streets of France in their largest numbers for several years today, Wednesday.

They are fighting a proposed new employment law that would tear up important workplace rights and make it even harder for young people to find a decent job.

Students were the driving force of the demonstrations, with hundreds of colleges and dozens of universities shut down on strike. They had held mass assemblies in the previous days to build the action, with more taking place this afternoon to organise their next steps.

Many cities saw big marches despite rain. Up to 20,000 took part in Toulouse and several thousand even in minor cities. The biggest turnout was in Paris where tens of thousands marched to the Place de la Republique square.

The president of UNEF, the main national students’ union, said that over 500,000 had taken part in marches across the country.

Student Raphael said, “We’re not just here for the employment law—we’re generally fed up. This was meant to be a government for the youth.”

Anne-Lise said, “I don’t have much hope for the future, but it’s important to be here and show we’re not happy.”

Several thousand people joined a separate demonstration called by the trade unions at the offices of bosses’ organisation Medef, then went to Republique for a united march.

Worker Flavie said the new law meant “People will be told to work longer hours until they burn out, instead of new hirings.”

Strikes

There were also some strikes, particularly in the transport sector where unions fighting over working conditions called the date to “bring together the struggles”.

Nationally two out of every three trains were cancelled, according to rail bosses. Hundreds of bus workers went inside the Paris bus network’s head office with flags, whistles and flares.

The transport shutdown had a huge effect—with over 350km of traffic jams across the region around Paris.

Strikes in the media also saw radio programmes replaced with music and disruption to the AFP news agency.

At the initiative of dockers’ unions, almost 1,000 protesters in the port town of Le Havre were up early at eight intersections to block all roads in and out of the town.

This is the biggest opposition the current Labour-type government has faced from the left and the workers’ movement since coming to office in 2012.

That reflects partly the viciousness of the proposed law which would help bosses to sack workers, increase their hours, or smash collective bargaining agreements.

It also reflects a growing frustration with a left government that promised everything and delivered nothing. Student union leaders talk of the straw that broke the camel’s back.

Prime minister Manuel Valls is seen as one of the main movers of the law. He has reportedly told hesitant ministers he will resign unless they step up to the plate and force the law through.

But many protesters would be happy to see him go.

In the biggest lecture theatre of Paris I University an assembly of hundreds of students chanted “Valls resign!” this morning. On the march into Republique they chanted, “Valls, you’re fucked, the youth is in the streets!”

At Rouen in Normandy, protesters splattered the offices of his Socialist Party (PS) with paint.

The movement has revived the spectre of previous youth movements—particularly the revolt that smashed the CPE youth law, which began ten years ago this month.

Today’s demonstrations were organised at shorter notice—and despite the new law not specifically targeting young people.

But for a generation the biggest strike and protest movements in France have been against Tory governments. With a PS government many unions are wary of causing trouble—something president Francois Hollande has used to avoid opposition to his austerity and repression.

Even now the large CFDT union federation is only demanding “substantial modifications” to the employment law.

Seven union federations had already set a date for joint mobilisations on Thursday 31 March. But both the government is setting a faster pace—and so are students, with a second day of action called on Thursday of next week.

At the general assembly in Paris VI university, student union activist Clement said, “One or two demonstrations won’t be enough—we’ll need a continuous mobilisation.”