Plaintiff S297/2013 v Minister for Immigration and Border Protection & Anor; Plaintiff M150 of 2013 by his Litigation Guardian Sister Brigid Marie Arthur v Minister for Immigration and Border Protection & Anor

These two cases, heard together, concerned the lawfulness of the detention of two asylum seekers, identified as Plaintiff S297/2013 and Plaintiff M150 of 2013, by the Minister for Immigration and Border Protection. The central dispute revolved around whether the prolonged detention of these individuals, who had been found to be refugees, was consistent with the constitutional framework of Australia, particularly concerning the executive power to detain. Gageler J of the High Court of Australia was tasked with determining the legality of this detention.

The primary legal issue before the Court was whether the executive power of the Commonwealth to detain non-citizens, as conferred by s 189(1) of the *Migration Act 1958* (Cth), could extend to the indefinite detention of a non-citizen who has been found to be a refugee. This question engaged the constitutional principle that the executive power of the Commonwealth is limited by the rule of law, which requires that detention be authorised by law and that such authorisation must be consistent with the constitutional separation of powers and the implied freedom of political communication.

Gageler J reasoned that the constitutional validity of s 189(1) of the *Migration Act* was not in doubt, as it provided a lawful basis for the detention of non-citizens who do not hold a visa. However, his Honour concluded that the executive power to detain, while broad, is not unlimited and must be exercised in accordance with the rule of law. The indefinite detention of a refugee, without any prospect of release or review, was found to exceed the constitutional limits of the executive power. This was because such detention, lacking a sufficient connection to the purpose of facilitating removal or processing, could not be justified as a necessary incident of the executive power to control the borders and immigration system. The Court held that the continued detention of the plaintiffs was unlawful.