The union allowed a second return-to-work order from the Canadian government to expire on Monday, halting the airline's operations for a third day.

The Canadian Union of Public Employees contends that the government’s decision on Saturday to end the strike by taking it to binding arbitration is itself illegal and violates its members’ constitutional right to strike. It filed an application for an injunction to block the back to work order with the Federal Court of Canada over the weekend.

Thousands of Air Canada flyers are facing another day of travel disruption on Monday, after striking Air Canada flight attendants defied a federal back-to-work order and abruptly halted the airline's plans to resume operations.