Three weeks after a strike at a refinery that has caused fuel shortages across the country, thousands of protesters are set to demonstrate in Paris on Sunday, adding to a growing picture of defiance and anger over inflation.

Sunday’s demonstration was called by left-wing political parties backed by hundreds of associations trying to build on the momentum created by the refinery standoff.

“You can see that this movement is starting to spread,” left-wing France Unbowed party parliamentary leader Mathilde Panot told Radio Franceinfo.

“You can see that in the nuclear sector. Truck drivers announced a stop on Tuesday and many other sectors are starting to join them,” she added.

Several French unions, but not all, have announced a national day of strikes for Tuesday, expected to affect road transport, trains and the public sector.

French energy giant TotalEnergies announced last Friday that it had reached a collective agreement with the two largest unions representing workers at its four refineries, raising hopes of an end to the standoff.

But the notoriously militant CGT union has refused to accept this and its members continue to picket lines.

Budget Minister Gabriel Attal condemned the continuation of the strike on Sunday as “unacceptable”.

“Of course there is a right to strike, but at some point the country has to be able to work,” he told French media.

Workers at two other Esso-ExxonMobil refineries returned to work late last week, but operations there will take two to three weeks to return to normal, the company said.

Around a third of petrol stations across the country are experiencing supply issues, particularly around Paris and in the north, meaning drivers often have to wait hours to fill up.

Many companies have reduced travel and deliveries, and even emergency vehicles are experiencing supply shortages.

Last week the government invoked emergency powers to force some striking tank farm workers to return to their jobs to release fuel stocks stuck in blocked facilities.

This enraged the CGT, which said the move was evidence of French President Emmanuel Macron’s “dictatorship”.

The huge gains made by energy companies from record fuel prices have prompted some sympathy for workers pushing for higher wages.

But a poll by the BVA polling group released on Friday found that just 37 percent of people supported the disruptions.

Sunday’s protest march through Paris was called by the France Unbowed party and is backed by its coalition partners – the Greens, Socialists and Communists.

Recently nominated Nobel Laureate in Literature Annie Ernaux and 60 other figures from the arts and public life issued a joint letter last week calling for people to join the march.

The main aim is to draw attention to the plight of workers grappling with higher costs – France’s inflation is at around 6.0 per cent – and to denounce inaction on climate change.

The police expect around 30,000 participants. According to one source, they feared trouble from anarchist groups, which regularly clash with security forces on the fringes of French protests.

“The organizer has been warned of these fears,” the official said.

The scale of the protests and strikes in the coming months could impact the government’s ability to push through a highly controversial pension system change.

Macron, who won re-election in April, has promised to push back the retirement age from 62 to bring France in line with its European peers.

But the idea is fiercely opposed by trade unions and left-wing parties.