The airline has warned that some flights would be cancelled over the next seven to 10 days and said that it "deeply regrets" customer inconvenience.

A labor relations board declared a strike by Air Canada’s 10,000 flight attendants illegal on Monday and ordered their union to tell them to return to work by midday.

“This is not a decision that I have taken lightly. The potential for immediate negative impact on Canadians and our economy is simply too great,” Hajdu told journalists, as reported by AFP.