Page:NZYQ v Minister for Immigration, Citizenship and Multicultural Affairs.pdf/25

Gageler CJ Gordon J Edelman J Steward J Gleeson J Jagot J Beech-Jones J

majority in Al-Kateb might be read as supportive of the legitimacy of the more expansive identified purpose, that reasoning was in tension with Lim.

The principle in Lim necessitates that the purpose of detention, in order to be legitimate, must be something distinct from detention itself. The terms in which the defendants couched the postulated purpose demonstrated its constitutional illegitimacy. If "separation from the Australian community" is equated with separation from the Australian community by means of detention, as was necessarily implicit in the defendants' formulation, then the postulated purpose impermissibly conflates detention with the purpose of detention and renders any inquiry into whether a law authorising the detention is reasonably capable of being seen to be necessary for the identified purpose circular and self-fulfilling. The submission that the detention of an alien can be justified by reference to a purpose which includes detention of an alien amounted to a submission that detention is justified consistently with Ch III of the Constitution if the detention is for the purpose of detention.

The defendants' attempt to rely on references in Lim to the detention of aliens being permissible as an incident of the executive power to exclude aliens as supportive of the postulated legitimate purpose of separation of an alien from the Australian community is misconceived. As Gleeson CJ explained in Re Woolley:

"Plainly [the plurality in Lim] did not contemplate that it is essential for a person to be in custody in order to make an application for an entry permit, or that it is only possible for the Executive to consider such an application while the applicant is in custody. They were referring to the time necessarily involved in receiving, investigating and determining an application for an entry permit. In a particular case, that time may be brief, or, depending upon the procedures of review and appeal that are invoked, it may be substantial. If a non-citizen enters Australia without permission, then the power to