French unions are staging a national day of strikes and demonstrations in opposition to the government's pension reforms - the third in a month.
Hundreds of thousands of people are expected to march in cities across France, with transport workers, civil servants and teachers stopping work.
Ministers want to raise the minimum retirement age from 60 to 62, and the state pension age from 65 to 67.
Meanwhile, key workers are set to vote on whether to begin open-ended strikes.
Half of all flights to and from Paris Orly airport, and one in three at Charles de Gaulle and Beauvais have been cancelled for Tuesday.
Just one in three TGV high-speed trains are expected to run. Eurostar's Paris to London route should operate normally.
Commuter trains in Paris were badly hit but the metro is less affected and buses should run as usual.
"This is one of the last chances to make the government back down," said Francois Chereque, the leader of the French Democratic Confederation of Labour (CFDT). "The large majority of employees cannot afford to pay for repeated days of strikes."
Hundreds of thousands are expected to protest on Tuesday, with more than 200 demonstrations planned nationwide.
One union representing elementary and nursery school teachers said it expected half its members would stay at home.
Further mass demonstrations are planned for Saturday.
The French oil industry has been hit. Workers at the Fos-Lavera oil port in southern France are striking for a 15th day, forcing up diesel prices in Europe. Diesel supplies have run out on Corsica.
Some 56 petrol tankers and 29 cargo ships are stranded outside Fos-Lavera port.
Ten of France's 12 mainland refineries have been affected. However, leading oil firm Total insisted supplies on the mainland were not being disrupted.
Public transport and energy sector workers will vote on Tuesday on whether to begin open-ended strikes.
These rolling strikes would be organised by serving notice of 24-hour stoppages and renewed each day before they expired.
Among those to have already declared in favour are union members from the state rail company, SNCF, and gas and electricity companies.
The French upper house, the Senate, is currently voting on the pension reform plans, article by article. The most contentious parts - raising the standard minimum retirement age from 60 to 62, and the age for a full state pension to 67 from 65 - have already been approved.
"We're not here to do what's easy, we don't always have the people's approval," Labour Minister Eric Woerth said. "It's difficult to tell the French that the they have to work more, up to 67 years, but it has to be done."
Last week, President Nicolas Sarkozy said he would inject more money into his retirement reform bill so some mothers could receive a full pension even if they had taken years out of work. The changes will be financed by new taxes that will bring in 3.4bn euros (£3bn).
But he said there would be no concessions on the key elements of the bill, which is expected to be passed by parliament in the coming weeks.
Splits
French workers can expect to spend more of their life in retirement than those in any other country, according to figures from the Organisation for Economic Co-operation and Development (OECD).
