OTTAWA -- Air Canada said Sunday it has suspended plans to resume limited flying on Sunday evening after its flight attendants defied a government back-to-work order.

The Canadian Union of Public Employees (CUPE) illegally directed its flight attendant members to defy a direction from the Canadian Industrial Relations Board (CIRB) to return to work, said Canada's largest airline in a news release.

It will resume flights as of Monday evening, said Air Canada.

Approximately 240 flights scheduled to operate beginning Sunday afternoon have been cancelled. Typically, Air Canada and its subsidiary Air Canada Rouge operate 700 flights a day, added Air Canada.

Canadian Minister of Jobs and Families Patty Hajdu issued a statement on Saturday saying that she exercised her authority under the Canada Labour Code to direct the CIRB to arbitrate the dispute between Air Canada and CUPE.

Despite eight months of negotiations on issues of compensation increase, ground pay, improved pensions and benefits, as well as increased crew rest, Air Canada has been unable to reach a tentative agreement with CUPE.