PARIS (Reuters) - French rail unions on Thursday called a wave of strikes, setting up a confrontation with President Emmanuel Macron as he tries to push through an overhaul of the state-run rail operator.

Reforming the debt-ridden state-run operator SNCF has long been a political hot potato in France. A previous bid in 1995 sparked paralysing strikes that forced the government to climb down.

The strikes planned from April 3 could be the one of the biggest challenges to Macron’s reform agenda since he took office last year.

On Wednesday the government backed a bill to fast-track through parliament the biggest shake-up since the railways were nationalised in the 1930s, including ending the right to jobs for life and removing early retirement provisions.

Four main railway unions on Thursday called for industrial action in response, although polls point to a lack of public support.

The rolling strikes will affect two out of every five days over a three-month period, the unions said, potentially bringing widespread travel chaos.

“The unions have realised that faced with an authoritarian government, we need to be prepared to take a combative stand over a very long period,” said Laurent Brun, head of the railway section of the CGT union.

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Macron is treading where past French leaders have shied away. The 1995 strikes prompted a u-turn from which prime minister Alain Juppe never recovered.

The battle over the future of the SNCF is as much a test of the mettle of unions, who have seen their influence decline since then, as for Macron’s stomach in driving through his economic reforms.

So far, the president appears to have public backing for his railway overhaul.

An Odoxa survey earlier on Thursday showed two in every three French believe widespread strikes would be an unjustified response. Respondents were also less convinced than previously that unrest could paralyse France as it has in the past.

“(The strike) would really penalise travellers, it’s not in anyone’s interest to be in a conflictive mindset,” Transport Minister Elisabeth Borne told BFM TV following the unions’ decision.

Macron is facing other signs of discontent over his reforms. Thousands of pensioners - a key voter constituency - marched through Paris and other cities in protest over higher social security taxes on Thursday.

Macron, a former investment banker, has also come under fire for scrapping a wealth tax and curbs on social housing aid.