What is the test for granting an interlocutory injunction?

Cyanamid v. Ethicon rejected the “prima facie case” concept in establishing the test now adopted by Alberta courts [p. 510]: The use of such expressions as “a probability”, “prima facie case”, or “a strong prima facie case” in the context of the exercise of a discretionary power to grant an interlocutory injunction leads to confusion as to the object sought to be achieved by this form of temporary relief. The court no doubt must be satisfied that the claim is not frivolous or vexatious; in other words, that there is a serious question to be tried. It is no part of the court’s function at this stage of the litigation to try to resolve conflicts of evidence on affidavit as to facts on which the claims of either party may ultimately depend nor to decide difficult questions of law which call for detailed argument and mature considerations. These are matters to be dealt with at the trial. One of the reasons for the introduction of the practice of requiring an undertaking as to damages on the grant of an interlocutory injunction was that “it aided the court in doing that which was its great object, viz abstaining from expressing any opinion upon the merits of the case until the hearing” (Wakefield v. Duke of Buccleugh (1865) 12 LT 628 at 629). So unless the material available to the court at the hearing of the application for an interlocutory injunction fails to disclose that the plaintiff has any real prospect of succeeding in his claim for a permanent injunction at the trial, the court should go on to consider whether the balance of convenience lies in favour of granting or refusing the interlocutory relief that is sought