Page:ASF17 v Commonwealth of Australia.pdf/25

Edelman J

NZYQ redux: two relevant requirements for a law requiring administrative detention of aliens

66 In NZYQ, this Court unanimously held that there were two requirements for the validity of a law that authorises or requires the detention of aliens. The law must have a purpose that is "both legitimate and non-punitive". A legitimate purpose is the "end" that is sought by Parliament. Hence, the first requirement is that the purpose or end sought to be achieved by the law must be legitimate. The purpose will not be legitimate if it is punitive (in the strict sense of "punishment"). But the law must also impose detention by an appropriate means to achieve that end: "the principle in Lim … requires an assessment of both means and ends, and the relationship between the two". Thus, the second requirement is that the relationship between means and ends must not be disproportionate. A law providing for the detention of aliens will be "punitive" (in a loose sense of punishment meaning "disproportionate") if the means that the law adopts are not reasonably capable of being seen as necessary for the end (or legitimate purpose) sought to be achieved.

67 As to the first requirement, in oral submissions in NZYQ the defendants had repeatedly emphasised that they were not submitting that "segregation, per se, is a legitimate purpose". They were correct not to make the submission that segregation (by detention) is a legitimate purpose. Detention is the thing to be justified by a legitimate purpose. Detention is not the purpose itself. Instead, the purpose relied upon by the defendants was described as segregation of aliens "[p]ending removal" from Australia and segregation of aliens "until such time as removal becomes possible". In other words, the focus of the defendants was on the general purpose of removal of aliens from Australia (and more particularly, those classes of aliens referred to in s 196(1)(a), (aa) and (b) of the Migration Act), even if that purpose was not able to be achieved for all aliens in the reasonably foreseeable future. But the conclusion of six members of this Court in NZYQ was that the asserted purpose of removal of an alien from Australia was "refute[d]" by "the absence of any real prospect of achieving removal of the alien from Australia in the reasonably foreseeable future". Their Honours considered that "[t]he terms in which the