Prime Minister Malcolm Turnbull and Opposition Leader Bill Shorten. Credit:Alex Ellinghausen The second failure was Malcolm Turnbull's; rather than junking the plebiscite proposal - one he argued against while communications minister - Turnbull acquiesced to the demands of party conservatives and retained it as part of the deal struck to install him as Prime Minister. But the third failure, now unfolding, belongs to Bill Shorten and members of the same-sex marriage lobby like Rodney Croome who used to support a plebiscite but now oppose it. Australia's 226 federal MPs are elected to cast votes and enact laws. That's why we pay their salaries. By announcing a plebiscite, Abbott and then Turnbull allowed MPs to duck their responsibility as our elected representatives.

Illustration: Cathy Wilcox But the plebiscite has been taken to an election and Turnbull did, actually, win - yet Shorten and Labor are all but certain to deny a national vote. They do this knowing full well that a plebiscite is very likely to legalise same-sex marriage in this country, as there are now more than enough MPs in each House who would vote for it, given the cover of a succesful "yes" vote in the plebiscite. Once again, the perfect looks to be the enemy of the good. Shorten and his team are correct to argue that a plebiscite is expensive; that it could unleash hate speech against same-sex couples; that MPs should actually be voting in the Parliament on the matter; and that a plebiscite is a radical departure from the usual practice of democracy in this country.

These are strong points, well made. But Labor, the Greens and the Nick Xenophon Team, all of whom support same-sex marriage, are effectively teaming up with the conservative forces in the Coalition and scuttling any prospect of same-sex marriage in the next three years. There is no guarantee that if the Coalition wins the next election that it would attempt to again hold a plebiscite. And it is eminently possible that, if Labor wins the next election and attempts to pass same-sex marriage into law through the Parliament, hate speech will be unleashed by those angry at being denied a popular vote and questioning the legitimacy of what some, at least, see as a matter of conscience. Labor's legal affairs spokesman Mark Dreyfus claimed on Monday that the government is "setting marriage equality up to fail" and that it had given no indication of where it might be willing to compromise.

Soon after, Attorney-General George Brandis fired back: "By my count, on some nine occasions, I said to them: 'What do you want?' I assured them that any proposal they made would be considered seriously by the government; would be considered in good faith and that I would take to the cabinet for consideration". It's no longer good enough for Shorten to simply stamp his feet and demand Turnbull give a free vote in the Parliament to his MPs. Labor is, in effect, demanding that Turnbull take a knife and cheerfully commit seppuku, the Japanese form of ritual suicide by disembowelment, on his own prime ministership. It's not going to happen. The Prime Minister supports same-sex marriage, as do many in his party, but there are large sections of the Coalition partyroom that do not.

If Turnbull learned anything from 2009, it is to not hurry faster than his partyroom. Indeed, as he made clear to Fairfax Media two weeks ago, he sees economic leadership as the key to a strong second term. Legalising same-sex marriage is not at, or near, the top of his list of priorities. Shorten knows this, but demands anyway. There is blame enough for all sides in this ridiculous stand-off. Loading

And meanwhile, same-sex couples are left in limbo, altar in sight but out of reach. Follow James Massola on Facebook