The Canada Industrial Relations Board has declared a strike by 10,000 Air Canada flight attendants illegal and ordered them back on the job after they ignored an earlier order to return to work and submit to arbitration.

Many travelers remain stranded after 10,000 flight attendants for Air Canada went on strike early Saturday over failed negotiations regarding wages. On Sunday, Air Canada said it could not restart operations as planned after flight attendants ignored a government order to return to work.

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,