Several hard-left trade unions in France are calling for a nationwide strike on Thursday to demand pay increases to cope with soaring inflation, threatening disruption to transport, schools and the energy sector.
The one-day walkout is seen as a test of the unions' ability to mobilise support and a barometer of potential social unrest as President Emmanuel Macron decides whether to push ahead with plans to reform the pension system.
The more moderate CFDT union has shunned the strike call, but its boss Laurent Berger has promised street protests later this year if the government goes too far and too fast on pension reforms.
Europe's cost-of-living crisis is putting upward pressure on wage inflation as private and public companies across the continent face demands from workers to cushion the impact of rising prices.
"Wages must be increased as there is a purchasing power problem in the country", Philippe Martinez, whose CGT union is spearheading Thursday's protests, told BFM television.
The CGT, whose membership includes transport and energy sectors, backs raising the minimum wage to 2,000 euros ($1,947.80) per month, a 32-hour week and retirement at 60. Martinez called on other unions to support the strike action.
"If we want to win, all the unions must be together," he added.
Striking CGT workers this week forced the shutdown of TotalEnergies (TTEF.PA) Gonfreville refinery and disrupted deliveries at others.
Nuclear power industry workers are expected to join Thursday's industrial action, removing some capacity from the French power grid when France already faces a record number of nuclear reactor outages.
In French primary schools, the SNUipp-FSU union expects one in every 10 primary schools to close in Paris.
Disruption to commuter train services into the capital and metro operations should not be severe, according to strike participation forecasts. On average two out of three buses are expected to run in the capital.
($1 = 1.0268 euros)