CUPE claims both sides walked away from the table after an Air Canada spokesman insulted the union and a federal mediator.
Labour Minister Lisa Raitt says she still expects the two sides in the Air Canada dispute to get back together and come up with a collective agreement.
The flight attendants have threatened to walk off the job at 12:01 a.m. tomorrow if their demands aren't met.
The key areas of dispute are wages, pensions, crew rest, working conditions and work rules.
