federal government had taken a range of actions, which they claimed were authorised under specific subsections of section 51. The Tasmanian government disputed these claims. External affairs power Section 51(xxix) of the Australian Constitution gives the federal parliament the power to make laws with respect to external affairs, a nebulously defined provision. The Hawke government passed the World Heritage Act under this provision, claiming that the Act was giving effect to an international treaty to which Australia was a party, in this case, the Convention Concerning the Protection of the World Cultural and Natural Heritage, which governs UNESCO's World Heritage Site program. The Tasmanian government (as well as the governments of Victoria, New South Wales and Queensland) opposed this action. Allowing the federal government such broad new powers would infringe on the States' power to legislate in many areas, and would upset the "federal balance". Chief Justice Gibbs said that although all of the Constitution is open to interpretation, "the external affairs power differs from the other powers conferred by s 51 in its capacity for almost unlimited expansion." Defining which affairs were of "international character" was a difficult task for the court. However, Justice Mason recognised that the external affairs power was specifically intended to be ambiguous, and capable of expansion. When the Constitution came into effect in 1901, there were few (if any) international organizations such as the United Nations in existence (not to mention multinational corporations). However, in modern times, there are many more areas in which nations cooperate. In his judgement, Justice Murphy said that in order for a law to have an international character, it is sufficient that it: implements an international law or treaty; implements a recommendation from the United Nations or a related body, such as the WHO or ILO; deals with relationships between bodies (public or private) within Australian and bodies outside; or deals with things inside Australia of international concern. It is important to note that the decisions of UNESCO in designating World Heritage Sites have no binding force upon any government. However, the ratification of the convention could be seen as a commitment to upholding its aims, and an acceptance of obligations under it. Corporations power Section 51(xx) provides that the federal government has powers to make laws regarding foreign, trading and financial corporations. Tasmania argued that this head of power could not apply to its Hydro-Electric Commission since it