France faces a first wave of rolling railway strikes on Tuesday that are expected to bring travel chaos in a test of President Emmanuel Macron’s resolve to modernize the French economy.

The four main rail unions have called two days of strikes in every five days for the next three months to protest against a shake-up of the national SNCF rail monopoly before it is opened up to competition as required by EU law.

The last time a French president squared off against rail unions over workers’ benefits it ended badly. The strikes of 1995 paralyzed Paris and forced prime minister Alain Juppe to pull the reforms, a defeat from which he failed to recover.

French unions are, however, weaker than in 1995 and divided in their response to Macron’s social and economic reforms. More than half of French people view the strike plan as unjustified, according to an Ifop poll published on Sunday.

“French people don’t want to put up with three months of chaos that has no justification,” Transport Minister Elizabeth Borne told weekend newspaper Le Journal du Dimanche.

The SNCF expects one the biggest strikes in years, with nearly one in two staff saying in advance they would take part. Commuter lines into Paris will be hit hard and only one in eight high-speed TGVs will operate, the SNCF has said.

International train services also face disruption: no trains will run between France, Switzerland, Italy and Spain. One in every three trains to Germany will operate, while the Eurostar service connecting London, Paris and Brussels will operate three out of every four trains, the SNCF said.

SNCF boss Guillaume Pepy, who backs the reforms, has warned of widespread disruption.

“I want to be very clear ... the strike action will no doubt be widely adhered to and his going to make the lives of a lot of people very difficult,” he said in a radio interview.