Editing Polyukhovich v Commonwealth (section)

==Decision==

===External affairs power===
By a majority of 6 to 1 (Brennan J dissenting) the court held that the Act was a valid exercise of the external affairs power. The six majority judges all wrote separate opinions. Mason CJ, Deane, Dawson, Gaudron & McHugh JJ were all of the opinion that as the subject matter of the legislation was external to Australia then the law was a valid one under the external affairs power. Mason CJ also said that if the Parliament considered that Australia had an interest or concern it was not for the court to examine whether there was a relevant interest or concern.

Toohey J, however, considered that it was not sufficient that the Act dealt with matters outside Australia. In his opinion, the subject matter had to 'touch and concern' Australia, In the event, he found that there was a sufficient connection between the subject matter of the Act and Australia to allow the law under section 51(xxix).

In dissent, Brennan J suggested that there must be a nexus between Australia and the 'external affair' involved. He held that, because the subject of war crimes in World War II was not an external affair at the time, i.e., 1939 to 1945, the subsequent acquisition of citizenship or residence in Australia by an individual was not enough to transform the subject matter into an external affair.

===Judicial power===
In relation to Polyukhovich's contention that the Act purported to usurp the judicial power of the Chapter III courts, the court held by a majority of 4 to 2 (Brennan J not deciding) that the statute did not invalidly usurp the judicial power of the Commonwealth. While the majority all accepted that a bill of attainder would offend the Commonwealth [[separation of powers]], the fact that a law operated ''[[Ex post facto law|ex post facto]]'' did not automatically make the law a bill of attainder. In addition, an ''ex post facto'' law of the kind under consideration was not a usurpation of judicial power.