As Air Canada cancelled flights on Thursday ahead of a possible flight attendants' strike, the union representing those workers accused the federal jobs minister of speaking "on behalf" of the company amid a contentious labour dispute.

Air Canada began cancelling flights on Thursday after receiving a strike notice from the flight attendants' union, warning all operations could be shut down by Saturday. Chief operating officer Mark Nasr told reporters Thursday that the airline had begun "a gradual suspension of Air Canada and Air Canada Rouge operations.

The Canadian government has urged Air Canada and its flight attendants' union to restart contract negotiations, with a threatened work stoppage that could disrupt travel for tens of thousands just hours away unless there is a resolution to the dispute.