Mark Hancock, National President of the Canadian Union of Public Employees (CUPE) which represents striking Air Canada flight attendants, speaks at a news conference in the hotel media room at Toronto Pearson International Airport in Mississauga, Ontario, Canada, August 18, 2025. REUTERS/Wa Lone

The Canada Industrial Relations Board had declared the strike illegal earlier on Monday and ordered the striking flight attendants back on the job. But the union said it will defy this second return to work order, after an earlier one had been ignored. The earlier one also ordered the union to submit to arbitration.

Striking Air Canada flight attendants vowed Monday to defy another back-to-work order from Canada's labor tribunal, extending a work stoppage that has cancelled travel for half a million people worldwide.