The Canada Industrial Relations Board had declared the strike illegal earlier on Monday and ordered the striking flight attendants back on the job. But the union said it will defy this second return to work order, after an earlier one had been ignored. The earlier one also ordered the union to submit to arbitration.

A Canadian government panel ordered the flight attendants back to work, but they refused. The strike is affecting about 130,000 travelers around the world each day.

Air Canada has suspended plans to restart operations after the union representing 10,000 flight attendants decided to defy a return-to-work order.