Air Canada and its unionized flight attendants remained at odds on Friday, despite government pleas for both sides to return to bargaining to avert a strike that would upend travel for tens of thousands of passengers.

The prospect of a systemwide work stoppage by Air Canada's unionized flight attendants loomed large on Friday with a strike deadline just hours away, despite a government plea for the two sides to return to the bargaining table.

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.