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.

The prospect of a systemwide work stoppage by Air Canada's unionized flight attendants loomed large on Friday with a strike deadline just hours away, despite a government plea for both sides to return to the bargaining table.

More than 10,000 flight attendants are poised to walk off the job around 1 a.m. ET on Saturday, followed by a company-imposed lockout if the two sides can't reach an eleventh-hour deal.