President Emmanuel Macron wants to raise the retirement age from 62 to 64, which has proven unpopular with French workers.
France is getting prepared for the impact of major transport blockages.
Mass strikes and protests are set to hit the country for the second time in a month, in objection to a planned reform to raise the retirement age.
Around one million people are expected to take to the streets nationwide, a police source told AFP, rallying against plans to boost the age of retirement from 62 to 64.
France currently has the youngest age for becoming a pensioner in any major European economy.
On January 19, some 1.1 million voiced their opposition to the proposed shake-up –– the largest protests since the last major round of pension reform in 2010.
Many people will have to find alternative means of transport, work from home or take time off to look after their school-age children on Tuesday, with workers in transport and education sectors among those staging walkouts.
Most Paris metro and suburban rail services will be severely restricted, the capital's transport operator RATP has said.
Intercity travel will also be disrupted, with just one in three high-speed trains running, national railway company SNCF has said.
Air travel is to be less badly affected, with national carrier Air France saying it would cancel one in 10 short and medium-haul services, but long-distance flights would be unaffected.
Only minor disruption is expected on international train services including the Eurostar.
Around half of all nursery and primary school teachers would be striking, the main teachers' union Snuipp-FSU said.
READ MORE: France braces for new strikes against Macron's controversial pension reform
Sixty-one percent of French people support the protest movement, a new poll by the OpinionWay survey group showed on Monday –– a rise of three percentage points from January 12.
The most controversial part of the overhaul is hiking the minimum retirement age.
But the changes are also to increase the number of years people have to make contributions before they can receive a full pension.
President Emmanuel Macron put pensions reform at the heart of his re-election campaign last year.
The 45-year-old centrist on Monday said the changes were "essential when we compare ourselves to the rest of Europe", where people typically retire later.
He insists they are necessary to guarantee the future financing of the pension system, which is forecast to tip into deficit in the next few years.
But opponents point out that the system is currently balanced, quoting the head of the independent Pensions Advisory Council as saying: "Pension spending is not out of control, it's relatively contained."
The government has signalled there could be wiggle room on some of the suggested measures, but Prime Minister Elisabeth Borne has said raising the age of retirement was "non-negotiable".
Parliament committees started examining the bill on Monday, where Macron and his allies also face an uphill battle.
The left-wing opposition has submitted more than 7,000 amendments to the draft legislation in a bid to slow its path through parliament.
Macron's centrist allies, short of an absolute majority, will need votes from conservatives to push through the new legislation.
READ MORE: French energy union distributes free gas in protest over pension reform