The first duty of a leader is to keep the team together. This is Malcolm Turnbull’s biggest failure. The federal parliamentary party is split, some of its strongest talent is banished to the backbench, party members are resigning in droves and the government is pursuing policies it would condemn coming from Labor.

Turnbull has never understood that loyalty is a two way street. You’ve got to give loyalty in order to get it. This involves fidelity to principles as well as loyalty to people. As leader of the Liberal Party, he has failed lamentably in his principal task, which is why he’s headed for a catastrophic defeat and should resign, as former Queensland premier Campbell Newman demanded last week.

The vociferousness with which some pro-Turnbull commentators declare that Tony Abbott has no party room support and the frequency with which Coalition ministers are trotted out to declare that Turnbull is leading a centre-right government indicates the extent of the PMs peril. Every statement by Turnbull that the team is united draws attention to disunity; every attack on Abbott draws attention to a rival whose record is looking better and better as time goes by.

As Bob Hawke often observed, if you can’t govern yourselves, you can’t govern the country. This week, the first anniversary of the election where he lost 14 seats, Turnbull was reduced to imploring his colleagues to be builders, not wreckers. Yet Turnbull is entirely to blame for the disunity he now laments. He tore down a democratically elected first-term prime minister and then trashed the low-tax, small government principles that used to characterise the Liberal Party. Other than himself, few think that he’s a good prime minister, and none of the arguments his supporters are using to sustain him actually stack up.

Turnbull and his senior ministers have justified the bank tax budget by saying that it’s all that could be expected to pass a left-dominated senate. It’s true that Labor has totally refused to take any responsibility for fixing the debt-and-deficit-disaster that is the current government’s inheritance. Even so, the argument that ‘the senate won’t do what we want so we have to do what the senate wants’ is an abdication of leadership. A real leader would try harder to get first-best measures through the senate or would find another way forward, such as the senate reform that Abbott is advocating. No real leader would do what he knows to be wrong on the basis that ‘someone made me do it’, yet that’s what some misguided commentators are currently using to excuse the government’s policy sell-out.

It’s true that the alternative to a Liberal government is a Labor one. But it doesn’t follow, as the Turnbull boosters claim, that the only alternative to Malcolm Turnbull is Bill Shorten. The alternative to Turnbull is a better Liberal leader – one who’s more likely to keep the party together and less likely to run a Labor-lite government. An obvious candidate is Abbott, who kept the party united over six years, whose 2014 budget was a serious attempt at long-term structural reform, and who got things done whenever he didn’t have to negotiate an intractable upper house. But if not Abbott, there are others. Julie Bishop might be Turnbull’s philosophical soul-mate but she surely wouldn’t repeat his mistakes of alienating conservatives and procrastinating on policy. Inadequate though he’s been, Scott Morrison has been less poor as treasurer than Turnbull has been as prime minister. Then there’s Peter Dutton, who is arguably the government’s strongest minister and who actually believes in the strong border protection policies he inherited. If Dutton became Liberal leader, he would stem the haemorrhage to One Nation and the Australian Conservatives and would have Abbott’s full backing to be prime minister.

Another argument used to keep Turnbull in office is that, having emulated Labor once in sacking a prime minister, you can’t emulate them twice and do it again. Just because it was wrong to replace Abbott doesn’t mean it would be wrong to replace Turnbull. Abbott, as an election winner, had a democratic legitimacy that Turnbull lacks, as a near loser. As well, Abbott had spent years in opposition doing the hard yards that Turnbull neglects: going to endless fundraisers, addressing party conference after conference, and meeting and placating the Liberal party grandees. Removing Abbott meant heavy transaction costs because of the indebtedness so many people felt. Beyond the inevitable conniptions in the commentariat, removing Turnbull would have no such consequences because most of the people who will miss him are those who are unlikely ever to vote Liberal.

For many Liberals, Turnbull’s statement on the weekend that he’d leave the parliament the moment he lost the prime ministership was confirmation that he has no real commitment to the party he leads. It was really a veiled threat: keep me or you’ll face a by-election that could cost you government. For a few months, it might keep cowed politicians who live for ministerial perks, but it will reinforce the remaining party loyalists’ fear that the current leader is an imposter.

For the moment, expect Team Turnbull to keep attacking Abbott as a wrecker and trying to show that all Turnbull’s troubles are somehow Abbott’s fault. But it wasn’t Abbott who unseated a prime minister; reversed the government’s economic direction; floated numerous policy ideas only to abandon them; repeatedly hung out his treasurer to dry; and added ‘2.0’ to Labor policies thinking that somehow made them Liberal!

If Turnbull could hold out a real olive branch to conservatives, stop edging ever closer to Labor on economic policies and on climate change, and bring himself to sound like a convinced and convincing centre right leader, he just might hold on.

But no one who knows Turnbull thinks that’s likely or even possible – which is why, in my judgment, his leadership has already passed the point of no return.