Dean Smith had what you'd call a bruising start to his federal political career.

Just a few months after he'd entered Parliament, replacing Judith Adams as Senator for Western Australia in 2012, he got a phone call from the Leader of the Opposition, Tony Abbott.

A witness to the call — from Mr Abbott's end — said nothing like it had ever been heard from him for the entire time he was Liberal leader.

Mr Abbott ripped into Senator Smith, calling him everything under the sun. A Glaswegian drunk would've blushed.

Senator Smith, who was over in Perth when he took that call, was taken aback by Mr Abbott's verbal barrage but, being the newest kid on the parliamentary block, assumed this was how federal politics was played. He knew no different.

Senator Smith's crime? He had been openly advocating WA MPs cross the floor in support of Labor's bid to deregulate the wheat industry, which was in defiance of Mr Abbott who'd backed in the Nationals' preference for a two-year deferral of any change.

An avowed federalist, Senator Smith was appalled that his WA colleagues should be expected to limply surrender on an issue so important to their state's grain growers.

He held firm and his agitation worked. Fellow WA Liberals Mal Washer and Dennis Jensen "absented" themselves from the vote in the Lower House, consoling each other over a bottle of cheeky Margaret River white wine, enabling Labor's bill to narrowly pass.

Mr Abbott was furious, but for Senator Smith it was an extraordinary victory. He had only been in the job for six months.

Senator Smith, the author of a private member's bill to legalise same sex marriage, knows what victory looks like in the shambles that is Parliament. Moreover, he knows how painful it is to stand up for what you believe.

He knows too, from his barney with Mr Abbott over wheat, about leaders' reflexive lurch for delay and obfuscation when hard decisions are, well, too hard.

Which is how the Coalition arrived at its current abysmal mess.

The unfulfilled pledge to have a plebiscite on legalising gay marriage is the Abbott ordnance that's lain un-defused beneath Malcolm Turnbull since he seized the prime ministership in 2015.

Next week may decide whether it kills him.

Mr Abbott as PM abrogated the responsibility that rightly belonged to Parliament, doing what he sought to do with the divisive wheat deregulation issue: simply kick it down the road rather than picking it up and dealing with it.

This is Mr Turnbull's stupid, yesteryear inheritance on same-sex marriage.

It's an appalling situation — a ninth or 10th order issue in the minds of most Australians has, by serial mismanagement and indecision, blown up into a full-blown crisis for Mr Turnbull.

Some in the Coalition pretend the plebiscite was a carefully conceived policy. It was anything but.

To those in the Government who remember how it all came about, it was particularly galling to hear Mr Abbott pronounce mid-week: "If it was good to put [a plebiscite] to the people at the last election, I don't see why it wouldn't be good to put it to the people at the next election."

The plebiscite was a bastard of a policy, emerging after a rambling, six-hour meeting on August 11, 2015. Even when the meeting was over, the Coalition's actual policy on same-sex marriage wasn't all that clear.

Sorry, this video has expired In 2015 Tony Abbott said 'this is the last term in which the Coalition party room can be bound' on same-sex marriage.

Mr Abbott told reporters that night that while a final position hadn't been settled, the "disposition" of the party was that it was a matter that should "rightly be put to the Australian people".

Of the 90 Coalition MPs who spoke during the meeting, only Liberal deputy leader Julie Bishop mentioned the word plebiscite — not as a firm proposal but more of a way of finding an honourable exit for her stubborn leader.

She spoke second to last in the meeting, before Mr Abbott. Hers was the only contribution Mr Abbott applauded.

Several Liberals, including veteran rainbow rights warrior Warren Entsch, don't remember the word "plebiscite" being specifically mentioned at all during the meeting.

But by the next day, Mr Abbott, ever the expert synthesiser of political message, boiled down the issue to a contest between a "people's vote" and a "politicians' choice", implicitly traducing the very institution he was expected to lead.

Yet two years later, the Coalition is still working out how it can bring the issue back to Parliament to be finally dealt with.

Because that's where this will end. All roads lead back to the House Representatives and giving coalition MPs and senators a free vote on the matter.

This is in effect what Liberal MPs will be discussing when they gather in Canberra on Monday for a special meeting.

A plebiscite, though intended as a stalling tactic by Mr Abbott, would, if successful, have seen the matter returned to the House.

So would a postal plebiscite.

But the plebiscite is a dead duck and the postal plebiscite, proposed by Peter Dutton as an alternative route, is intensely problematic.

Neither type of plebiscite would be compulsory. Nor would they be binding.

Senator Smith and fellow rebels Mr Entsch, Tim Wilson, Trent Zimmerman and Trevor Evans demand there be no more delay. There are many other Liberals who want it dealt with too, including supporters of the traditional definition of marriage.

Even Mr Abbott has privately conceded to allies in recent weeks that like-minded conservatives will lose the fight against same sex marriage sooner or later. He acknowledges the community had moved beyond the Parliament on this issue.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 8 minutes 7 seconds 8 m Emma Alberici speaks to Warren Entsch about the upcoming meeting.

Notably, after that marathon meeting two years ago, Mr Abbott said: "If we were starting from scratch this almost certainly would be a free vote", before adding, "but we're not starting from scratch".

Yet he publicly suggests Mr Turnbull stick with a policy that has proved ruinously distractive from bigger, more important issues on the economy, energy and national security.

The PM's choices are dastardly.

Those of his colleagues who say he has no option but to abide by the plebiscite policy for the remainder of this term underestimate the determination of the rebels to bring this to a vote next week.

And the postal plebiscite would face immediate hostility, constitutional question and probable legal challenge.

Mr Turnbull, the cosmopolitan self-made millionaire whose positions on climate policy, tax reform and gay marriage made him the go-to candidate when Mr Abbott failed, would face more ridicule.

And promise of a free vote on same-sex marriage next term may not convince the Liberal rebels to withdraw.

Faced with such appalling choices, the best worst decision might be for the Prime Minister to take a stand that properly reflects his own views, not the tortured indecision of his predecessor.

After all, no Prime Minister ever knows how long they've got.