Union leaders for Air Canada’s flight attendants said members would return to work after a deal was reached to end a three-day strike that grounded hundreds of flights, hitting around 500,000 customers.

Air passengers are still scrambling to rebook their flights home as a labour dispute between Air Canada and its flight attendants continues to ground planes around the world.

The Canadian Union of Public Employees said it will challenge an order by the Canada Industrial Relations Board to return to work by 2 p.m. ET.