MONTREAL — The union representing Air Canada flight attendants says its workers remain on strike despite a back-to-work order.

The Canadian Union of Public Employees (CUPE) says it will challenge an order by the Canada Industrial Relations Board to return to work by 2 p.m. ET.

The federal government said Saturday that it was ordering the airline and its flight attendants back to work, ending a strike and lockout after less than 12 hours.

Air Canada had planned to resume flights today after the federal government stepped in and ordered binding arbitration.

The airline said more than 700 Air Canada and Air Canada Rouge flights have been cancelled during the work stoppage.

CUPE says it is inviting Air Canada back to the table to negotiate a fair deal.