French flag-carrier Air France said it expected to cancel around 40 percent of its long-haul flights and 30 percent of shorter journeys as aviation workers went on strike for a third day.

The airline, the firm the worst hit by the industrial action, urged customers to postpone travel and has sent out thousands of emails and text messages to clients warning them their flights had been cancelled or delayed.

The strike hit services at Paris's Charles de Gaulle airport, a global aviation hub, as well as several French regional airports.

Unions called the four-day strike to protest against a draft law that would 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.

Transport Minister Thierry Mariani said on Monday that the government would not drop the bill, which he said would protect passengers' rights.

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