151 Section 5B is a provision that defines what constitutes discrimination on the ground of gender identity. It is not itself a provision to which any constitutional head of power is directed. The concept of gender identity discrimination, so defined, is then used throughout the SDA, including in provisions proscribing this and other forms of discrimination. Section 5B therefore gives content to other parts of the Act which entail the exercise of legislative power to proscribe such discriminatory conduct. Sections 5 to 7A similarly define other forms of discrimination on the ground of sex, sexuality or intersex status, marital or relationship status, pregnancy or potential pregnancy, breastfeeding, and family responsibilities. Various provisions in Pt II of the SDA then prohibit discrimination on these grounds, including in work, education, the provision of goods, services and facilities, and so on. Ms Tickle relies on s 22, which prohibits several kinds of discrimination, including on the ground of gender identity, in the provision of goods, services and facilities.
152 The respondents mistakenly challenge the constitutional validity of s 5B, rather than s 22 to the extent that it prohibits discrimination on the ground of gender identity. The challenge therefore purports to have an impact on this aspect of the SDA as a whole. However, the specific question that properly arises on the facts in this case is whether s 22, read with s 5B, goes beyond Commonwealth legislative power to the extent that it prohibits discrimination on the ground of gender identity in the provision of services. It is appropriate to deal with the respondents' constitutional challenge on this basis, rather than take the available easy option of dismissing it as misconceived. The conclusion reached on that question necessarily has a parallel impact on other provisions that proscribe gender identity discrimination in other areas, which also apply the terms of s 5B to give content to those proscriptions.
153 Section 9 of the SDA, dealing with the application of that Act, is drafted with a view to the scope of, and limitations upon, Commonwealth legislative power: see, AB v Registrar of BDM at [7] (Black CJ, dissenting, although not on this point). Section 9(4) relevantly provides that "the prescribed provisions of Part II … have effect as provided by … the following provisions of this section and not otherwise". Section 22 is a "prescribed provision" of Pt II: s 9(1). Section 5B is in Pt I of the Act, so is not itself a prescribed provision to which s 9 is directed.
154 The "following provisions" in s 9 refer to various heads of constitutional power in the Constitution. Relevantly:
- (a) section 9(10) provides that the prescribed provisions, which include s 22, are to be given effect to the extent that they give effect to a "relevant international instrument",Tickle v Giggle for Girls Pty Ltd (No 2) [2024] FCA 96045
