Air Canada suspended plans to resume flights Sunday after striking flight attendants refused a government order to return to work.

The union defied a government order to return to work. The airline said it would delay plans to restart operations from Sunday until Monday evening.

Air Canada said it suspended plans to restart operations on Sunday after the union representing 10,000 flight attendants said it will defy a return to work order.

Air Canada wants to reinforce the gender wage gap by forcing Air Canada flight attendants – 70% of whom identify as women – to accept a wage offer less than one-third what Air Canada offered its pilots less than a year ago.

The Canadian government has urged Air Canada and its flight attendants' union to restart contract negotiations, with a threatened work stoppage that could disrupt travel for tens of thousands just hours away unless there is a resolution to the dispute.

The Canadian carrier said it expects to call off 500 flights by the end of Friday. Air Canada said it was suspending its schedule and trying to get passengers booked with other airlines to limit disruptions.