A statistically small minority's issue has become the majority's headache, and incompetence, dithering and backbiting from our politicians has merely made things worse, writes Terry Barnes.

According to the Australian Bureau of Statistics, the 2011 census found about 33,700 same-sex couples in Australia. About 17,600 couples were male and 16,100 female.

These represented about 1 per cent of all couples in Australia.

Last year, Roy Morgan Research asked how many Australians are homosexual. They found that in 2006-08 about 2.4 per cent of people identified themselves as homosexual. In 2012-14, this increased to 3.4 per cent.

Clearly, the number of people coming out in that time had increased, yet the number of self-identified gay Australians is still just one in 29 of the total Australian population.

Sure, these numbers are indicative, and definitions of what they represent are contestable. But when it comes to Australian politics, and as we appear to be staggering towards a July double-dissolution, they also say that in the last two-and-a-half years a great deal of time, emotion and political capital has been thrown at an issue not greatly relevant to the everyday lives of the vast majority of Australian voters.

It's consumed acres of newsprint, thousands of hours of airtime and polarised social media. It helped bring down one prime minister, put another under heavy political pressure, and split the Liberal and National parties. It has unified the Australian Labor Party against the Coalition, yet as a conservative Labor senator's resignation showed last week, it split it too.

That issue, of course, is same-sex marriage. Rarely can one minority issue directly affecting so few dominate so many.

It's made the Coalition look all at sea in managing itself. Former PM Tony Abbott cobbled enough support together in a hopelessly fractured Coalition party room to foist a decision on a same-sex marriage plebiscite on the Australian people like that successfully held last year in Ireland. His nemesis, Malcolm Turnbull, pledged to continue with the plebiscite when he challenged Abbott for the Liberal leadership, even if it was against all his progressive instincts.

With an election looming, Attorney-General George Brandis on Sunday said that the plebiscite, costing more than $160 million, would be held before the end of this year. Yet by Sunday night the PM's office slapped Brandis down, saying only that it would be held "as soon after the election as can be done", and Treasurer Scott Morrison indicated he'd campaign for a "no" vote and said the plebiscite vote itself should be compulsory.

A progressive Liberal, new Liberal MP Trent Zimmerman, declared his unequivocal support for same-sex marriage in his maiden speech; a conservative Labor senator, Joe Bullock, decried it in his last speech.

MPs like Liberal Cory Bernardi declared they will die in a ditch for traditional marriage and reject the result of the plebiscite if it approves same-sex marriage.

As well as Labor and the Greens, Liberals like Western Australian senator Dean Smith are now calling for the plebiscite to be dropped and let a parliamentary vote do the job. And to highlight his rainbow credentials, Labor Leader Bill Shorten is coming dangerously close to calling Liberals bigots: last week labelling Bernardi a "homophobe" and yesterday accusing conservative Liberal MPs of "persecuting" Zimmerman.

What a mess.

Our national agenda has been reduced to incompetent chaos, and civil public discourse is fraying, for about 4 per cent of the Australian population. This must stop.

Let's make our national representatives earn their salaries. Those of us (and I was one) who felt a plebiscite was the best of all worlds, giving us all a say on a fundamental social issue, the definition of marriage, were wrong.

Dean Smith, as conservative a Liberal as you can find, said yesterday:

I'm uncomfortable with the cost, secondly I'm uncomfortable with us too readily abrogating the foundational principle of parliamentary sovereignty.

Personally, I prefer the traditional definition of marriage, but Smith is right. We live in a parliamentary democracy, and we elect our MPs to not only represent us but to use their own judgment on the big issues of the day. As great conservative thinker, and Abbott hero, Edmund Burke put it almost 250 years ago:

Your representative owes you not his industry only, but his judgment; and he betrays, instead of serving you, if he sacrifices it to your opinion.

So let's scrap the expensive plebiscite and put same-sex marriage to a free, parliamentary vote. Let's charge our MPs with using their judgment, consulting widely, listening to their constituents for and against, and voting after a thoughtful parliamentary debate. That's why we elect them, isn't it?

If Turnbull promises a free vote after the election, as he should, Shorten must stop his grandstanding, make clear Labor MPs will not be bound on the issue, and work with the Prime Minister to lower the emotional temperature Shorten's own unstatesmanlike antics helped fuel. And if individual voters consider candidates' views on same-sex marriage as a vote-changer in the imminent election, that's democracy in action.

But if there must still be a plebiscite, Turnbull must clarify its terms and timing before we go to the polls. Voters are entitled to be clear about what they are effectively endorsing at the election. And with the Government having taken the easy way out and devolved MPs' responsibility to the people, the PM must make it crystal clear to the people that all Coalition MPs will be honour-bound to legislate the outcome of the plebiscite, the will of the people, whatever it may be.

We all should be tolerant and respect difference and diversity - on both sides of this debate - but same-sex marriage has utterly hijacked the national agenda. A statistically small minority's issue has become the majority's headache, and our politicians' incompetence, dithering and backbiting merely have made things worse.

Drop the plebiscite, Prime Minister. The controversy over same-sex marriage must be resolved decisively by Parliament so we can all move on. It and its divisiveness have paralysed our politics for too long.

Terry Barnes is a policy consultant, former senior Howard government adviser and a weekly columnist for The Drum. Twitter: @TerryBarnes5.