Canadian Union of Public Employees, or CUPE, which represents the flight attendants, refused to voluntarily submit to arbitration. “The appropriate course of action is for Air Canada to return to the table and resume good faith bargaining,” it said in a statement.

Air Canada expects to cancel the majority of its estimated 700 daily flights on Friday, ahead of a planned Saturday strike by unionized flight attendants, leaving some 100,000 passengers scrambling to make alternative travel plans.

Air Canada is preparing to cancel hundreds of flights before a potential flight attendant strike that is set to take place on Saturday.