It will be as if they had not married at all.

But the symbolism will have been important.

Gay couples have five days from when the law becomes operational and when the High Court has said it will rule on the validity of the law.

When the High Court comes back on December 12 it is likely to give its decision and orders on the ACT’s same-sex marriage law and publish its reasons later.

The court has several choices: to rule that the law is inconsistent with the Commonwealth Marriage Act and therefore invalid, or to rule that it is not inconsistent and that the law is valid; or to rule that the meaning of the word “marriage” in the Constitution precludes same-sex unions.

The basic constitutional position is that the states have full power to legislate for whatever they like unless and until the Commonwealth decides to legislate with respect to any of its powers listed in the Constitution.

If the Commonwealth chooses not to exercise its power, then the states are free to legislate. For the purposes of this exercise the territory is in a similar position as a state.

One of the Commonwealth’s listed powers is “marriage”. The Commonwealth did not legislate in the area until 1961. Before that, marriage was covered by state law.

In 1961 everyone assumed that a marriage, by the very definition of the word, could only mean a marriage between a man and a woman. Recent events have changed that perception.

The question of whether the ACT law is inconsistent with the Commonwealth law is a bit tricky.

The ACT has argued that there is nothing inconsistent between its law providing solely for same-sex unions and the Commonwealth law which provides solely for unions between a man and a woman.

But the constitutional test is not just a question of logical or practical inconsistency. There is another constitutional doctrine that goes wider than that.

The High Court has held in the past that if the Commonwealth legislation evinces an intention to “cover the field” then there is no room for state legislation and any state legislation in that “field” is invalid.

For example, a state could not legislate for a scheme for some form of top-up medical or pharmaceutical benefits, because the Commonwealth Medicare and PBS legislation clearly evinces and intention to cover the field of those kinds of benefits. It would not matter that the state law was not strictly logically and practically inconsistent.

So the test for the High Court will be whether the Marriage Act evinces an intention to “cover the field”. The Commonwealth says it does.

In a 2004 amendment to the Marriage Act, the Commonwealth added a definition clause. It reads: “‘marriage’ means the union of a man and a woman to the exclusion of all others, voluntarily entered into for life.”

The court will have to decide whether that is a legally effective statement that covers the field leaving no room for state or territory same-sex marriages.

Or it might hold that it is an invalid attempt to define the word “marriage” in the Constitution when the Constitution says it is for the High Court to determine the meaning of words in the Constitution, not for the Commonwealth Parliament.

Another option would be to hold that the word “marriage” in the Constitution means only a union of a man and a woman and that is the limit of Commonwealth jurisdiction, leaving it open to the states to legislate for same-sex unions or marriages.

If the High Court holds that the Commonwealth has covered the field, then the ACT law and all the things done under it would be void, as if they had not happened. The court has held in the past that it has no power to give any validity to acts done under invalid laws. The state or territory law is in abeyance as if it had never been enacted unless the Commonwealth repeals its legislation – which simply will not happen.

The court would have no power to somehow validate this weekend’s marriages.

What typically happens in these cases is some sort of remedial Commonwealth legislation is enacted to deal with any nasty consequences. But I cannot imagine the Commonwealth legislating to save the same-sex unions entered in to this weekend.

If, on the other hand, the law is held valid, then if the Commonwealth wanted to ensure no state or territory could provide for same-sex marriages it would have to legislate to make it clear that it wanted to cover the field of marriage.

It would be quite simple. The legislation would go something like this:

1. “Marriage” in this Act means the same as the word “marriage” in the Constitution.

2. Marriages can be created only under this Act.

3. Marriages under this Act can only be between a man and a woman.

That would have been the legally smart thing to do in 2004 with a less hostile Senate if the Howard Government wanted to put paid to any idea of the states legislating for same-sex marriages.

But no, the conservatives were more interested in making an ideological statement, than a legal one. Hence, the High Court case and all the uncertainty that has gone with it. It is really anyone’s guess as to how the court might interpret the 2004 amendments and the Marriage Act in general.

Incidentally, if the court holds that the word “marriage” in the Constitution means only unions between a man and a woman we will need a referendum before we can have same-sex marriages in Australia.

All that said, the ceremonies in the ACT this weekend will have a profound social and psychological effect whatever the court says. People will see that the sky will not fall in. It will make same-sex marriages more acceptable and hasten the time when there will be a national law providing for same-sex marriages. Anything less is unsatisfactory. Even if the ACT law is held valid we would still have one law for gays and another for everyone else.

www.crispinhull.com.au