Opinion on Constitutional Validity of Tasmanian Same-Sex Marriage Bill

This opinion on the constitutional validty of state same-sex marriage legislation was written by Melbourne University constitutional law expert, Associate Professor, Kristen Walker.

It is my view that the Bill to provide for same-sex marriage under Tasmanian law would be a valid law of the Tasmanian Parliament, if passed. My reasons for this view are as follows:

1. Although the Commonwealth has constitutional power over marriage, this power is not exclusive of state power. As with the Commonwealth heads of power generally, the states retain power over topics assigned to the Commonwealth.

2. Thus, prima facie the Tasmanian Bill is within the power of the Tasmanian Parliament.

3. However, where the Commonwealth exercises its constitutional powers, then if a state law is inconsistent with a Commonwealth law, the state law will be invalid or "inoperative" to the extent of the inconsistency.

4. In this case, the Commonwealth has exercised its legislative power over marriage by enacting the Commonwealth Marriage Act. Thus the question is whether the Commonwealth Marriage Act would be inconsistent with the Tasmanian Same-Sex marriage Act, if passed.

5. The only relevant form of inconsistency is known as "covering the field" inconsistency. That is, has the Commonwealth in the terms of the legislation evinced an intention to "cover the filed", ie to regulate the area exclusively, so that there is simply no room for state legislation?

6. There are two aspects to this test: (1) what is the field that the Commonwealth law regulates; and (2) did it intend to regulate exhaustively?

7. it is my view that, having regard to the terms of the Commonwealth Marriage Act, the field that that Act regulates is the field of opposite sex marriage. This si because the Act regulates such marriages only. This is made quite clear in the definitional section , which provides that in this Act, marriage means "the union of a man and a woman …". The Act does not purport to regulate same-sex marriages. Nor does it purport to define marriage generally; the definition is simply a definition of the term "marriage" as used in the Marriage Act. Thus it is my view that the field that the Marriage Act deals with is the field of opposite-sex marriage.

8. It is my view that the Commonwealth does intend to cover the filed on opposite sex marriages; but this does not render the Tasmanian bill inconsistent with the Commonwealth Act.

9. Alternatively, one can ask if the state law "impairs or detracts from" the operation of the Commonwealth Act. It does not appear that the Tasmanian Act, if passed, would do so, as it regulates an entirely different field and does not impact on the recognition of opposite sex marriages at all.

10. I acknowledge that there is room for difference of opinion on these issues. But it cannot be said that the Commonwealth Marriage Act would clearly render the Tasmanian Act, if passed, invalid.


KRISTEN WALKER
Associate Professor of Law
University of Melbourne