The Howard Government sought to bring as many employees under "WorkChoices" as was within its constitutional powers. It relied on the corporations power (Section 51(xx) of the Constitution of Australia) extending its coverage to an estimated 85% of Australian employees. All employees of "constitutional corporations" (i.e. trading, financial, and foreign corporations) became covered by the "WorkChoices" system. Other constitutional powers used by the federal government to extend the scope of the legislation included the to cover the Australian territories, including the external territories of the Christmas and Cocos Islands, the external affairs power, the interstate and overseas trade and commerce power, and the powers of the Commonwealth to legislate for its own employees. Victoria had voluntarily referred its industrial relations powers to the Commonwealth in 1996, under section 51(xxxvii) of the Constitution.