0650 GMT January 20, 2021
The overhaul, unveiled this week by Prime Minister Edouard Philippe, would do away with the 42 separate pension systems – some of which offer early retirement and other benefits to public-sector employees such as train drivers, dockers and even Paris Opera employees, AFP reported.
Philippe angered unions further by proposing a reduced payout for people who retire at the legal age of 62 instead of a new, so-called "pivot age" of 64.
Strike organizers have announced a massive protest for Tuesday when tens of thousands are expected to take to the streets again.
Unions are hoping for a repeat of 1995, when they forced a rightwing government to back down on pension reform after three weeks of metro and rail strikes just before Christmas.
The prospect of a protracted standoff has businesses fearing big losses during the crucial yearend festivities, and travelers worried that their holiday plans will fall through.
Philippe told the Parisien daily in an interview for its Sunday edition that the French would not accept being "deprived" of festive transport options.
"I can well see that everyone is worried as they see Christmas near. Christmas is an important time," he said.
On Friday, he asked SNCF (the French National Railway Company) chief, Jean-Pierre Farandou, to draw up a list of exactly which trains would be running during the festive season.
But the unions have said they will not give in – and that the government would have to.
"If the government wants the conflict to end before the holidays, they have all of next week to take the wise decision and scrap the point-based pension plan," Laurent Blum, the general secretary of the hardline CGT-Cheminots, the main SNCF union, told AFP.
France's moderate CFDT (Democratic Confederation of Labour) union joined the action after the government's announcement that those who retire before the "pivot age" of 64 would not receive a full pension.
"It's very simple: For the CFDT to take another look at this bill, the government must agree to withdraw the pivot age. One point, that's all," CFDT leader, Laurent Berger, told Le Journal du Dimanche.
"It is deeply unfair to ask those who were born in 1960 and who are due to retire in 2022 to work longer," he added.
If the government does not give ground, the CFDT will also call for industrial action in January, after Tuesday's strike, said Berger, who is not opposed to reform of the current pension system.
Berger said CFDT railway workers did not want a strike over the holiday season.
"I don't wish to block transport for Christmas. We should not make users pay the bill... We have to break this deadlock," he said.
The prime minister has held talks with union leaders and more negotiations are scheduled over the coming week.
Philippe on Friday struck a combative note, saying he "has absolutely no fear of implementing this reform".
The architect of the overhaul, pensions commissioner Jean-Paul Delevoye, has been hit by suspicions of conflicts of interest after several omissions in his declaration of interests, which he has since amended.
Under the French constitution, members of the government are prohibited from carrying out "any professional activity" in addition to their official functions.
The prime minister however stressed Saturday that he had faith in Delevoye and dismissed talk of his resignation.