The eight public sector unions urging workers to walk off the job are confident they'll see a response from both the public and private sectors.
Mainline SNCF trains will be severely disrupted Thursday, with the Paris suburban RATP network announcing expected delays on the metro, and RER lines A and B.
Teachers, postal workers, health workers and those in the judicial system have all filed strike notices, while public television and radio stations are primed to stop work. Following suite are staff within the telecom and energy industries, and in museums.
"The priority is to widen mobilisation," said Bernhard Thibault, the head of the CGT union, adding that the previous day of action, on 7 September, may have been hindered by the fact that many French had recently returned from summer holidays.
The unions said 2.5 million people went on strike, with 220 protests held across France, while the Interior Ministry said the figure was considerably lower, at 1.12 million.
Despite this last call to arms, timed to coincide with a parliamentary debate on the issue, the reform bill passed through France's National Assembly, and is to be examined by the upper house in two weeks, where it is expected to pass.
The reforms are intended to avoid large and growing deficits in the pension system as people live longer and baby boomers start to reach retirement age.
Under current rules, the French can retire at age 60 if they have paid social security contributions for 40.5 years, although they are not entitled to a full pension until they are 65.
If the reform bill is finally adopted, the retirement age will go up to 62 by 2018, and the pension age to 67, and workers will have to pay social security contributions for an extra year to get a full pension.
French President Nicolas Sarkozy said the reform stands to save 70 billion euros by 2030, at a time when France's public deficit of about 8 percent of GDP is well above the
eurozone target of 3 percent.
After the 7 September protests, Sarkozy said there was “no question of backtracking" on raising the retirement age. But he did make some concessions, promising exceptions for those who start work younger than 18 and those who work in physically demanding jobs.
Unions and opposition politicians say the reforms plan puts an unfair burden on workers.
On Friday morning, an inter-union meeting will decide on further action, with some calling for an open-ended strike from 24 September.
A survey carried out for the CGT union and published Tuesday in the communist newspaper L'Humanite said that 70 percent of French were opposed to raising the retirement age.
The public sentiment comes at a time when Sarkozy’s approval ratings are at an all-time low, and less than two years before he seeks re-election.