French rail users are facing a fourth two day-strike since April. The industrial action by union members is likely to cause major disruption and comes just hours after a parliamentary vote approved President Macron's controversial railway reforms.
Only one in every three high speed TGVs is expected to be running. Regional TER trains will also be hit although Eurostar will have a near-normal 4 out 5 trains operating.
The showdown between government and rail unions is scheduled to last for at least another month, and possibly until June.
Tuesday's approval in France's National Assembly was a significant step towards President Emmanuel Macron's flagship reforms becoming law. The bill abolishes the SNCF's passenger rail monopoly and ends protective job-for-life contracts.
The confrontation is Macron's biggest test so far in his bid to see through a raft of economic forms. But its also a challenge for commuters as well as SNCF staff whose pay is cut each time they refuse to work. France is braced for more rail disruption.