French flag-carrier Air France expects to have to cancel around 40 per cent of its long-haul flights and 30 per cent of shorter journeys for today, it said, half-way through a four-day strike.
The company said it had been able to operate around 70 per cent of its scheduled services on Tuesday, as aviation workers pursued a strike against plans to require them to give 48 hours notice of a walk-out.
After causing limited disruption on Monday, the four-day strike by pilots, flight attendants and airport staff gained momentum.
Journalists at Paris's Charles de Gaulle airport, a global aviation hub, confirmed that large numbers of journeys had been cancelled, including flights to Milan, Algiers, Marseille and Sofia.
Air France codeshares with Qantas on flights from Australia, which are unaffected, but connecting flights from Asia to Paris were hit, including today's AF257 from Singapore to Paris and AF185 from Hong Kong to Paris. A Qantas spokesperson said passengers who had booked their flights with Qantas would be accommodated on other flights.
Flight disruptions had been limited on Monday, with Air France able to fly 85 percent of long-haul and 75 per cent of short- and medium-haul flights.
The company urged customers to postpone travel until after the strike and sent out more than 25,000 emails and mobile phone text messages to clients warning them their flight had been cancelled or delayed.
French regional airports were particularly hard hit, with Marseille seeing 59 flights cancelled and 51 cancelled in Toulouse.
The aviation workers voted on Friday to launch a nationwide strike from February 6 to February 9.
Unions are protesting a draft law that will require aviation workers to individually give 48 hours notice prior to striking, saying this limits labour rights.
The bill was approved by France's lower house last month and is due to be debated in the Senate.
Labour leaders vowed the strike would gather support, with Yves Deshayes, the head of the SNPL pilots' union, saying "the mobilisation will reach a crescendo".
The union said half of Air France pilots were on strike.
"Over the next few days it will be more and more complicated for Air France to guarantee its flights," said an activist with the PNC flight attendants' union, who spoke on condition of anonymity.
Transport Minister Thierry Mariani said on Monday that the government would not drop the bill, which he said would protect passengers' rights.
"We will go all the way. This is necessary and that is something the French people understand," he said on RTL radio.
Air France-KLM meanwhile said that its January passenger traffic rose 3.7 per cent while cargo traffic dropped 10.3 per cent due to the weakening economy and the timing of the Chinese New Year this year.