Air Canada says the Canada Industrial Relations Board has declared the strike by the company’s 10,000 flight attendants unlawful and has ordered the union's leadership to direct its members to return to work.

10:35 a.m. The Canadian Union of Public Employees says a strike by 10,000 flight attendants at Air Canada will continue, defying an order from the Canada Industrial Relations Board that it provide public notice by noon ET that it had ended the strike.