The applicable principles that govern whether to grant an interlocutory injunction were identified by the High Court in Australian Broadcasting Corporation v O’Neill.[  HCA 46; (2006) 227 CLR 57, Gleeson CJ and Crennan J , Gummow and Hayne JJ –. See also Beecham Group Ltd v Bristol Laboratories Pty Ltd  HCA 1; (1968) 118 CLR 618 andAustralian Broadcasting Corporation v Lenah Game Meats Pty Ltd (2001) 208 CLR 199, –.1]
(a) The plaintiff must demonstrate a prima facie case. This requirement is to be understood as whether there is a serious question to be tried as to the plaintiff’s entitlement to relief, not whether it is more probable than not that the plaintiff will succeed at trial. The sense in which the test is understood is that the plaintiff must prove, prima facie, a sufficient likelihood of success to justify, in the circumstances, the preservation of the status quo pending trial. In context, it must show that it has a putative legal or equitable right in respect of which final relief is sought which will justify the restraint sought. The requisite strength of the probability of ultimate success depends on the nature of the rights asserted and the practical consequences likely to flow from the interlocutory order sought.
(b) The balance of convenience must favour the granting of an injunction. The balance of convenience requires a consideration of the relevant matters favouring or militating against the granting of an injunction and will necessarily involve a consideration of the strength of the plaintiff’s claim assuming that a serious issue has been identified. In Victoria, this consideration is further clarified by the decision of the Court of Appeal in Bradto Pty Ltd v Victoria. The court must, in determining whether to grant an interlocutory injunction, “take whichever course appears to carry the lower risk of injustice if it should turn out to have been wrong, in the sense of granting an injunction to a party who fails to establish his right at the trial, or in failing to grant an injunction to a party who succeeds at trial”.