ParisAuthorities expect up to 700,000 marchers on Thursday.
Five unions want a higher minimum wage, currently €12.31 an hour, and protected public services.
Student protests across France since September spread to workers, and violence on 17 October left more than 2,000 stores looted.
The government released 10 million barrels of diesel from strategic reserves to cut fuel costs.
Interior Minister Laurent Nuñez has deployed 70,000 police and warned of black blocs, looting and wildcat marches.
How each outlet framed it
drawn from 70+ reports worldwide
- BBC
- adds energy stakes: refineries asked to halt production and France expecting net electricity imports from nuclear outages
- Deutsche Welle
- cites 17.5% of primary teachers expected to strike and EDF power unions joining, linking the walkout to the October 17 riots
- TEMPO.CO
Sources: BBC, Deutsche Welle, TEMPO.CO