Summer travelers are facing uncertainty as the clock winds down on a possible strike by Air Canada flight attendants, which the airline said would force it to cancel almost all of its scheduled flights as soon as Saturday.

Air Canada has canceled hundreds of flights — many of them international flights — as a potential strike by flight attendants looms.

Air Canada's unionized flight attendants walked off the job early on Saturday morning after contract talks with the country's largest carrier stalled, in a move that could disrupt travel plans for more than 100,