Air Canada had planned to resume operations of Air Canada and Air Canada Rouge flights on Sunday after those flights were grounded on Saturday due to the labour disruption, but the airline said it was not able to resume operations due to “CUPE leadership’s unlawful strike activities.”

Air Canada and Air Canada Rouge have been grounded since Saturday due to CUPE's labour disruption. The airline now estimates 500,000 customers' flights have been cancelled as a result.

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 Mo