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.

The dominant air carrier in Canada set in motion a process that could ground 130,000 passengers a day by Saturday.

It's the final day before a potential work stoppage could ground all Air Canada and Air Canada Rouge flights. More than 10,000 flight attendants are poised to walk off the job around 1 a.m.