Canada’s government forced Air Canada and its striking flight attendants back to work and into arbitration Saturday after a work stoppage stranded more than 100,000 travelers around the world during the peak summer travel season.

The union representing 10,000 Air Canada flight attendants said it will challenge an order to return to work and remain on strike.

A walkout by flight attendants ended after about 12 hours with the imposition of binding arbitration. But getting travel back to normal will take days.