Manitoba (A.G.) v. Metropolitan Stores Ltd., [1987] 1 SCR 110, 1987 CanLII 79 (SCC)
http://canlii.ca/t/1ftq5
• Manitoba legislation empowered Labour Board to impose collective agreement in certain circumstances
• Metropolitan Stores was challenging the constitutionality of the act, and wanted to enjoin the Labour Board from acting until the constitutionality of the provision was decided
• Court imports test from American Cynamid Co. for granting of injunctive relief
• Decides that the balance of convenience must also include considerations of public interest – cannot pretend that statutory authority distinct from the public interest it represents
• From Headnote: The first test is a preliminary and tentative assessment of the merits of the case. The traditional way consists in asking whether the litigant who seeks the interlocutory injunction can make out a prima facie case. A more recent formulation holds that all that is necessary is to satisfy the court that there is a serious question to be tried as opposed to a frivolous or vexatious claim. The “serious question” test is sufficient in a case involving the constitutional challenge of a law where the public interest must be taken into consideration in the balance of convenience. The second test addresses the question of irreparable harm. The third test, called the balance of convenience, is a determination of which of the two parties will suffer the greater harm from the grant or refusal of an interlocutory injunction, pending a decision on the merits.