Their union says one of its core demands, to receive pay for groundwork, is unlikely to be introduced in arbitration. The airline began canceling flights ahead of the potential strike.

Summer travelers are facing uncertainty as Air Canada flight attendants threaten to strike this weekend. The airline plans to cancel hundreds of flights on Friday and potentially halt all operations

Air Canada began canceling flights Thursday ahead of a possible strike by its flight attendants that could impact hundreds of thousands of travelers. A complete shutdown of the country's largest airline threatens to impact about 130,000 people a day.