Canada’s largest union is suing the federal government to stop it from ever again invoking the controversial legal tool the Liberals used to order striking Air Canada flight attendants back to work.

Aviation analytics firm Cirium said that as of Monday afternoon, August 18, Air Canada had called off at least 1,219 domestic flights and 1,339 international flights since last Thursday, when the carrier began gradually suspending its operations ahead of the strike and lockout.

Air Canada and the union representing Canadian flight attendants have reached a tentative deal to end the strike that started Saturday. It will resume flights.