Plaintiff M47/2018 v Minister for Home Affairs & Anor

The High Court of Australia considered the case of Plaintiff M47/2018, who sought to challenge the lawfulness of their detention and the validity of certain decisions made by the Minister for Home Affairs and the Department of Home Affairs. The plaintiff, an asylum seeker, had arrived in Australia by boat and was subsequently detained. The core of the dispute concerned the Minister's power to issue a 'removal pending assessment' (RPA) visa, which the plaintiff argued was invalidly issued and resulted in unlawful detention.

The central legal question before the Court was whether the Minister had the constitutional and statutory authority to grant a visa that would permit the detention of a non-citizen, who had arrived unlawfully, for the purpose of assessing their claims for protection. Specifically, the Court had to determine if the *Migration Act 1958* (Cth) conferred such power, and if so, whether that power was consistent with Chapter III of the *Australian Constitution*, which vests the judicial power of the Commonwealth exclusively in the courts. The plaintiff contended that the RPA visa scheme effectively allowed for executive detention that usurped the role of the courts in determining lawfulness of detention.

The High Court, in a majority decision, found that the Minister did possess the power to grant an RPA visa under the *Migration Act*. The majority reasoned that the Act provided a framework for the management of non-citizens who arrived unlawfully, including the possibility of detention for assessment purposes. Crucially, the Court held that the grant of such a visa did not constitute an exercise of judicial power, as it was an administrative act aimed at managing immigration and border security, rather than a determination of guilt or innocence or the resolution of a dispute between parties in a manner characteristic of judicial proceedings. The Court distinguished this power from the core judicial functions of determining the legality of detention, which remained within the purview of the courts.

The High Court dismissed the plaintiff's application, upholding the validity of the RPA visa and the Minister's power to issue it.