The union for 10,000 striking Air Canada flight attendants says they won’t be returning to work despite an administrative tribunal declaring the work stoppage illegal

Air Canada Cargo is operating a temporary freighter schedule to mitigate the disruption, offering capacity to several airports across the U.S., Mexico, South America and Europe.

Air Canada CEO Mike Rousseau said on Monday the airline was "amazed" by the decision of its flight attendants' union to defy an order by the Canada Industrial Relations Board, which has declared the union's strike unlawful.