The union representing 10,000 flight attendants for Canada's largest airline issued a 72-hour strike notice on Wednesday.

Air Canada has canceled most of its flights over the next few days to prepare for a strike by flight attendants. Some travelers may end up stranded as a result.

Air Canada said on Thursday it expects to cancel several dozen flights by day's end and around 500 flights by the end of Friday affecting 100,0000 passengers, ahead of a planned Saturday strike by its unionized flight attendants.