Transport and public services in France are expected to be disrupted as unions demonstrate against proposals to raise the retirement age from 62 to 64.
On Tuesday, the majority of train and metro services are cancelled, and many schools will be closed.
Since mid-January, there have been six days of strikes and demonstrations, and unions predict this one will be the biggest yet.
At protests in Paris and other cities, over a million people are anticipated.
One union leader claimed that there is a discussion of escalation and “bringing the country to its knees” because the administration is not showing any signs of reversing course on its pension proposal.
There will be requests to prolong the strikes in crucial industries including gas terminals and electricity generation in the coming days.
Despite the clamour and occasional disruption, the campaign has so far not significantly hurt the economy, and the law is still making its way through parliament.
Unions and the left are increasing the pressure now because they are aware that there is a limited amount of time remaining until the change is a fait accompli.