A Tasmanian Greens bill to legalise gay marriage is attracting significant attention in the national media. UNSW constitutional lawyer George Williams is being touted by supporters of the bill as advising that it may well survive constitutional challenge (somewhat ironically) because a 2004 Howard government amendment to the Marriage Act (Cth) may have opened a “loophole” that would allow the Tasmanian law to avoid constitutional invalidity for inconsistency with the Commonwealth law by operation of Constitution section 109.
The question potentially arises because the Commonwealth’s marriage power (section 51(xxi) is a concurrent one, not an exclusive Commonwealth power), so that the States can legislate on the subject of marriage as long as the State law isn’t inconsistent with any Commonwealth one dealing with marriage.
I haven’t seen Williams’ detailed advice, but the media summaries of it suggest that Williams is arguing that the Marriage Act amendment may have had the effect of making it “cover a field” of legislative operation separate from that of the proposed Tasmanian law, thus avoiding any inconsistency. However, although it’s an ingenious argument, I have my doubts that it would succeed.
The recent Commonwealth amendments essentially just added an additional definition of “marriage” in section 5:
marriage means the union of a man and a woman to the exclusion of all others, voluntarily entered into for life.
Williams presumably argues that this definition evinces an intention to deal only with the field of heterosexual marriages, leaving the (separate) field of gay marriage open to be occupied by a State law without any inconsistency (and therefore invalidity of the State law). But that conclusion surely depends on the legislative intention of the Commonwealth Act. I would have thought that, putting it at its very highest, the 2004 amendment results in an ambiguity. Did the Commonwealth intend to legislate only for heterosexual marriage, leaving the field of gay marriage clear for the States? Or did it intend to define marriage exhaustively for all purposes as meaning only heterosexual marriage? That is, did the Commonwealth in fact intend to occupy the entire field of “marriage” at least to the extent of defining exhaustively what types of union it includes?
At least since the enactment of sections 15AA and 15AB of the Acts Interpretation Act (Cth) in the early 1980s, the approach in such a case of ambiguity is then to look to the object and purpose of the provision, and in so doing one may examine extrinsic sources including the Minister’s Second Reading Speech and other sources that may reveal the government’s intention. You wouldn’t have to look very hard at any extrinsic source to discover that the Howard government’s intention was to exhaustively define marriage and to exclude the possibility of gay marriage.
Moreover, that conclusion is fortified by looking at the 2004 amendments themselves, which not only inserted the purely heterosexual definition of marriage but also precluded the Australian recognition of any overseas gay marriages. It’s hardly likely that the Commonwealth intended to preclude gay marriages under Commonwealth law and the recognition of overseas ones, while leaving the States free to legislate for gay marriage if they so desired.
In addition, the “cover the field” test for section 109 inconsistency, on which Williams’ advice apparently relies, is not the only test for constitutional inconsistency. It is sometimes referred to as the “indirect” inconsistency test. The more usual direct test looks at whether there is a direct “collision” between a provision of the Commonwealth law and a provision of a State law. Does the Commonwealth law remove or modify a right which the State law then purports to restore (or vice versa)? If so, then there is a direct collision and the State law is invalid to the extent of the inconsistency. Again, it’s probable on this test that a State law which defined marriage as including gay marriage and a Commonwealth one which excluded such marriages would be held to be in direct collision.
However, maybe there is an argument that has some (although probably less than 50%) chance of success. It might be argued that the Commonwealth’s constitutional power in relation to marriage (section 51(xxi)) is confined to legislating in respect of heterosexual marriage. Simply because that is what “marriage” meant in 1901 when the Constitution was enacted. The argument depends on the High Court adopting an “originalist” approach to the meaning of “marriage” in the Constitution. The Court has sometimes been minded to hold that words used in the Constitution must be regarded as bearing the meaning they held in 1901, but has sometimes (and probably more often in recent years) held that the meaning of constitutional words can evolve with contemporary understandings, at least where it’s reasonable to conclude that the Founding Fathers would have intended such an evolving meaning.
Justice McHugh mused about this very issue in Re Wakim; Ex parte McNally in 1999:
Thus, in 1901 “marriage” was seen as meaning a voluntary union for life between one man and one woman to the exclusion of all others. If that level of abstraction were now accepted, it would deny the Parliament of the Commonwealth the power to legislate for same sex marriages, although arguably “marriage” now means, or in the near future may mean, a voluntary union for life between two people to the exclusion of others.
If the Commonwealth lacks the constitutional power to legislate in relation to gay marriage, does that mean that the States, whose “residual” legislative power is “full and plenary” to the extent not excluded by Commonwealth power, would have that power? Quite possibly.
I certainly hope the Tasmanian Greens get ALP support for their gay marriage bill, not only because I see no compelling reason why the unions of gay couples shouldn’t be legally equal in all ways to heterosexual marriages, but because the law will inevitably be challenged in the High Court and we’ll end up with a fascinating decision about not only section 109 inconsistency but also approaches to constitutional interpretation.