Parliamentarians should have a conscience vote on gay marriage

Until the Marriage Act is amended, a national civil union scheme would not be seen as an alternative for couples who don't want to marry, but as a poor substitute for same-sex couples who do want to marry, a substitute which no supporter of equality should accept.

So would such a scheme become law if Labor put it forward? The Coalition has said it would oppose a national civil union scheme leaving the casting vote in the hands of the Greens. They have said civil unions are not a substitute for full equality but it worries me that they have refused to declare they will vote a civil union scheme down before marriage equality is achieved.

So far I have only considered options for the future of marriage equality in the federal sphere. Talking of state civil unions raises the possibility of state same-sex marriage laws.

According to constitutional experts like professor George Williams, the marriage power in the federal constitution is shared between the federal and state governments. If the Feds do not legislate for a particular type of marriage, in this case marriage between people of the same sex, that power falls to the states. On the basis of this advice the Tasmanian Greens have twice introduced same-sex marriage laws. I understand MPs in other states are seriously considering going down the same path. I support this.

Another path to be considered is a court challenge to the constitutionality of discrimination in the federal Marriage Act. The section of the Constitution that gives the Federal Government the power to make marriage law does not define marriage as a different- sex union. On top of that, Australia has international obligations to ensure there is no legal discrimination on the grounds of sex and sexuality.

There's also an argument that marriage discrimination violates the free practice of those churches which currently solemnise same-sex marriages. But don't get too excited.

The High Court may well decide that marriage should be defined in the same way the Edwardian gentlemen who framed the Constitution saw it – as a different-sex union. It would also probably put weight on those international human rights decisions which have maintained the right to legal equality does not apply to marriage. It would probably reject the argument for religious freedom.

That brings me back to the final option for moving marriage equality forward: a parliamentary conscience vote.

In my lobbying last week I found strong support for a conscience vote among MPs in both major parties. They could see it is much more likely than some far-off party vote and much more desirable than the compromise of a national civil union scheme. They also know a conscience vote would be a popular move. Last week's poll showed a marriage equality conscience vote has the support of 78 per cent of Australians.

On the back of this support, Australian Marriage Equality has established a new website to make it easier for people to make their support for a conscience vote known to the leaders of the major parties. The address is www.freevote.org.au and I understand 3000 people have already sent through letters.

A conscience vote has its critics. The Prime Minister objects to it, pointing out it is Labor's practice to work as a team. Some people closer to the issue fear the anti-gay hate campaign it may unleash, or the loss of momentum if the vote goes against equality.

I am not so concerned. A well-funded anti-equality campaign is inevitable, no matter which path the nation goes down. If that campaign veers into hate, the cause of equality can only benefit.