Air Canada flight attendants have defied a return-to-work order issued by the federal government, and will remain on strike.The Canadian Union of Public Employees said they wouldn't budge until the airline is willing to "negotiate a fair deal.""We will be challenging this blatantly unconstitutional order that violates the Charter rights of 10,000 flight attendants, 70% of whom are women, and 100% of whom are forced to do hours of unpaid work by their employer every time they come to work," CUPE said in a statement, per the CBC. The announcement comes just hours after Air Canada released a statement informing customers that it intended to restart flight operations in accordance with Minister of Jobs and Families Patty Hajdu's directive..The airline has since suspended that plan and said it will instead resume flights Monday evening.."Canadians rely on air travel to connect families, workers, and communities to each other and the world," Hajdu said on Saturday. "Despite significant supports from the government, these parties have been unable to resolve their differences in a timely manner. The government must act to preserve stability and supply chains in this unique and uncertain economic context."That is why I exercised my authorities under section 107 of the Canada Labour Code to direct the Canada Industrial Relations Board to arbitrate this dispute," she continued. "I am exercising this authority because it is critical to maintaining and securing industrial peace, protecting Canadians and promoting conditions to resolve the dispute. Despite the parties’ resolution of several key differences, the CIRB is best positioned to help them find a solution on the outstanding items."Air Canada flight attendants have asked for better wages, and to be paid for their entire work day, not only the time in which they are in the air.