France was already paralysed Thursday morning by a nationwide strike by transport workers, teachers and other professionals in a showdown between unions and President Emmanuel Macron over his planned pension reforms.
Some 90 percent of high-speed trains have been axed, most of the Paris metro will be shut, hundreds of flights cancelled and the majority of schools closed in the strike.
With some air traffic controllers also walking out,.said it was axing 30 percent of its internal flights and 15 percent of short-haul international routes.
British low-cost carrier EasyJet has cancelled 223 domestic and short-haul international flights and warned others risk being delayed.
The strike -- which is open-ended and could last several days -- has drawn comparisons with the struggle between government and unions in November-December 1995 when the country was paralysed for around three weeks.
Workers across France will have to stay at home or find novel ways to access their offices using car-sharing services, rental bikes or e-scooters.
The strikes will be a major test of whether Macron, who came to power on the back of a promise to transform France and has also sought a prominent place on the international stage, has the political strength to push through his vision.
The president is seen as having seen off the threat posed by the "yellow vest" protesters whose weekly demonstrations against inequality shook France from November last year.
But their anger could feed into the strike movement called by the unions and a transport strike on September 13 that caused gridlock in Paris might prove a harbinger of things to come.
"The moment of truth for Macron," wrote the Le Monde daily in Thursday's edition. "The next days are a decisive test for the head of state."
The Mediapart website added: "Will the protests and strikes be strong enough to halt the march of reform? Everyone is holding their breath."
On the Paris metro, 11 of the city's 16 lines will shut down completely Thursday, with only the two fully automated lines running as normal.
Rail operator SNCF said 90 percent of high-speed TGV trains as well as regional services across the country would be cancelled, while international routes like the Eurostar and Thalys would be severely disrupted.
Education Minister Jean-Michel Blanquer said he expected 55 percent of teaching staff to strike nationwide Thursday, with 78 percent walking out in Paris, and just 30 percent of schools being able to open.
Macron wants to implement a signature campaign promise that would see a "universal" retirement system.
It would do away with 42 "special regimes" for sectors ranging from rail and energy workers to lawyers and Paris Opera employees, which often grant workers higher pensions or early retirement.
6,000 police deployed
But unions say the changes would effectively require millions of private-sector workers to work beyond the legal retirement age of 62 if they want to receive the full pension they have been promised.
Prime Minister Edouard Philippe, who has acknowledged French workers will gradually work longer, is set to unveil details of the reform on December 12.
Interior Minister Christophe Castaner said Wednesday that 245 demonstrations were expected nationwide, warning that a radical fringe of protesters could cause trouble.
Paris police chief Didier Lallement said around 6,000 members of the security forces would be deployed in the capital alone, with 180 motorbikes used to respond fast to any rioting.
Two major demonstrations are planned for Paris that will converge on the Place de la Nation, with officials ordering Paris businesses along the routes to close