Attendants union says there is still time to reach an agreement, as airline warns 100,000 passengers affected by Friday.

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 has started cancelling flights in advance of a 72-hour strike by cabin crew staff that will leave its fleet of aircraft “completely grounded’.