In Polyukhovich v The Commonwealth [1] , Mason C.J., Deane J., Dawson J., Gaudron J. and McHugh J. all expressed the conclusion that a law with respect to a matter which is territorially outside Australia is a law with respect to "External affairs" for the purposes of s. 51(xxix) of the Constitution [2] The other two members of the Court, Brennan J. and Toohey J., considered that some additional factor was necessary. Brennan J. [3] was of the view that s. 51(xxix) confers power to enact "laws affecting affairs" which are geographically external to Australia only if there "be some nexus, not necessarily substantial, between Australia and the "external affairs" which [the] law purports to affect". Toohey J. [4] was of the view that, even though geographically external to Australia, a "matter does not qualify as an external affair" for the purposes of s. 51(xxix) unless it be one "which the Parliament recognises as touching or concerning Australia in some way". Regardless of whether the mere fact that a matter or thing is territorially outside Australia is of itself sufficient to bring a matter or thing within the phrase "External affairs" for the purposes of s. 51(xxix) or whether one or other of those additional factors is necessary, it is clear that the area of the Timor Gap and the exploration for, and the exploitation of, petroleum resources within that area all fall within that phrase. Each of those matters is geographically external to Australia. There is an obvious and substantial nexus between each of them and Australia. As the enactment of the Act demonstrates, they are all matters which the Parliament recognizes as affecting or touching Australia. That being so, the enactment of a law with respect to one or all of those matters is prima facie within the legislative power conferred by s. 51(xxix).