Air France has urged customers to reschedule flights or exchange their tickets free of charge rather than wait for the outcome of the negotiation currently taking place with trade unions.

Unions earlier said rejected an offer by the airline aimed at resolving the dispute, instead extending the ongoing strike at the airline until September 26th.

Air France had earlier offered to postpone the plan to create Transavia subsidiaries in Europe - outside France and the Netherlands - while entering into extended talks about the project and building together the necessary guarantees by the end of the year.

A comprehensive negotiation and explanatory process with Air France and KLM unions will be set up.

However, pilots represented by the SNPL union said a proposed suspension was a “smokescreen” that offered no more guarantees than previous offers.

The strike, which has now been ongoing for eight days, is the longest at Air France since the late 1990s.

Pilots are protesting over the firm’s plan to expand Transavia because they fear it will drive down their wages as jobs are moved across to the low-cost carrier.

The strike has been costing the airline upward of €10 million a day, with France’s transport minister Alain Vidalies on Sunday saying the fate of the carrier was “at stake”.

Air France said it expected to operate nearly half of its flights on Monday.

“Air France has maintained constant dialogue with its pilots in order to reach an agreement to benefit the Group’s growth and competitiveness,” said Frédéric Gagey, president, Air France.

“I deplore that our concrete proposals to reassure our pilots have not been met with a reasonable response as yet.

Air France flights operated by other airlines, including HOP!, KLM and Delta, are running as normal.