The union defied a government order to return to work. The airline said it would delay plans to restart operations from Sunday until Monday evening.

The looming Air Canada flight attendant lockout has the potential to cause havoc to travel plans in Canada and America. Air Canada announced it will begin canceling flights Thursday in anticipation of the lockout,

The Canadian carrier said it expects to call off 500 flights by the end of Friday. Air Canada said it was suspending its schedule and trying to get passengers booked with other airlines to limit disruptions.