Section 51(xx) of the Australian Constitution

Section 51(xx) of the Australian Constitution, is a subsection of Section 51 of the Australian Constitution that gives the Commonwealth Parliament the power to legislate with respect to "foreign corporations, and trading or financial corporations formed within the limits of the Commonwealth". This power has become known as "the corporations power".

After the High Court's 1909 decision in Huddart, Parker & Co Ltd v Moorehead, the "corporations" power was largely ignored as a basis for Commonwealth legislation. The majority judges agreed in this case that the power should be construed narrowly, though they were unable to agree on any appropriate interpretation. Their approach reflected the perceived need to protect "the reserved powers of the States", an idea abandoned in 1920 as a result of Engineer' case.Justice Issacs dissent in Huddart, Parker gave a broad meaning to s 51(xx) but attempted to set limits to the power, in particular pointing out:

It was not until Huddart Parker was overruled in Strickland v Rocla Concrete Pipes Ltd that the modern development of the power began. In that case, the leading judgment was delivered by Chief Justice Barwick, who, although agreeing that Isaacs' dissent in Huddart Parker conformed to the reasoning in Engineers, refused to define the scope of the corporations power. He stated instead that "the decision as to the validity of particular laws yet to be enacted must remain for the Court when called upon to pass upon them".

The Incorporation Case confirmed that the ambit of the corporations power extends only to corporations that have already been formed, and, therefore, it does not include the power to incorporate them. It extends only to domestic corporations of a trading or financial character, and to all corporations formed outside Australia, and they are collectively referred to as "constitutional corporations".

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