When Angus Taylor executed his coup against Sussan Ley earlier this year, he didn't just topple a struggling leader. He established a ruthless benchmark. 

Ley, the federal Liberal Party's first female leader, had been in the job for less than a year following a devastating election defeat.

The party was sliding backwards, the polls were ugly, and the Liberal brand was bleeding voters. Therefore she had to go, so the argument went. Fair enough. Politics is brutal, and being Opposition leader isn't an entitlement.

That was Taylor's test - not mine, his. And now it applies to him too.

Taylor launched his challenge declaring that 'the Labor government has failed and the Liberal Party has lost its way'. He insisted the party needed 'strong and decisive leadership', warning that Liberals were 'running out of time' to fix the situation.

He was right about that last bit. But since Taylor seized the leadership, the Liberal Party hasn't found its way. In fact, it has sunk even further into the electoral swamp. One Nation's support continues to rise, while the Coalition's primary vote keeps falling.

Pauline Hanson is capitalising on housing shortages, record migration and cost of living pressures that the Coalition seems unable to turn into a coherent political argument of its own.

That's now Taylor's fault and the clock is ticking on his leadership. He gave Ley a paltry nine months before deciding she wasn't up to the task at hand. Taylor has already used up half that amount of time making a bad situation even worse. If he survives to the end of this year, he'll have been leader longer than Ley was.

Which is why a senior Liberal parliamentarian put it this way to me this week: 'Angus set up his own yardstick for success or failure, and at the moment he's failing.

'He's got until the end of the year to get it right. If he can't turn things around by then, he needs to go early in the new year so that we can reset under someone else and have a fighting chance of saving the furniture at the next election.' 

That is the conversation now taking hold inside the Liberal Party, whether Taylor's office admits it or not.

The Coalition has devolved from a government in waiting into a political carcass, circled by a populist insurgency it once patronised.

The Ley benchmark is unforgiving. Taylor's coup was sold as an emergency intervention to arrest a terminal decline.

Nobody framed that intervention more starkly than Senator James Paterson, the most vital strategic figure on the Liberal right. Paterson can't lead from the Senate, giving him a different, more lethal power. He is a factional operator with the ability to make and unmake leaders. He may soon need to tap Taylor on the shoulder.

When Paterson broke with Ley, he did not hedge his bets. He stated that he no longer had confidence in her ability to 'turn this ship around'. He called it a 'change or die moment' for the Liberal Party, arguing that the 'best way' to show voters the party had changed direction was 'to change leaders'.

Those words now sit like an unexploded ordnance under Taylor's leadership. That same moment is fast approaching.

If changing leaders was the best proof of a new direction in February, what is the best way to prove it if the party is still bleeding support come November, or February next year? 

Paterson may not want to answer that just yet, but you can bet he's thinking about it. He may believe Taylor deserves more time than Ley was given, or that a party suffering from a decade of policy drift can't be repaired in a few months. But that logic applied to Ley too, yet she wasn't given any quarter.

This is a trap Taylor built for himself. Having argued that drift is fatal, he can't now ask his colleagues to admire the scenery while the party continues to drift. The harder question is, who replaces him?

The leadership cupboard isn't completely bare, but it's hardly overflowing. That's what happens when you lose so many seats and don't adequately renew either.

Realistically, there are three options.

Andrew Hastie is the leading conservative option, but he is divisive internally. The lingering bitterness around the Ben Roberts-Smith saga means he excites some Liberals while alarming others.

Tim Wilson is the moderate alternative. He's articulate and understands the metropolitan seats the Liberals have haemorrhaged at recent elections, managing to win his seat back from the teals at the last election. But Wilson risks being perceived as too progressive by conservatives.

This pair may need to run as a unity ticket to replace Taylor, but can they agree on the order? It's reminiscent of Alexander Downer and Peter Costello from the mid-1990s when they ran together to replace John Hewson. It didn't work, of course, and John Howard stepped in, going on to win the 1996 election and serve as PM for eleven and a half years. Second only to Robert Menzies.

But there is no Howard waiting in the wings. The closest consensus-style candidate is Dan Tehan. He's from the regions and has plenty of cabinet experience, unlike the other two. He's also less ideologically provocative. But he's not remotely inspiring.

A former Liberal minister summed the contenders up to me like this:

'None of them particularly excite me, to be honest. Two of them are very inexperienced, and the third is too bland to excite the electorate or reclaim support from One Nation. I'm not sure what they can do, it's a mess.'

That is the Liberal Party neatly summed up in one quote.

Yet the three alternatives share one motivation: self-preservation. Hastie, Wilson, and Tehan will all probably lose their seats under Taylor's leadership unless things change. Not that they would be alone amongst colleagues in that respect. Few Liberals and virtually no Nationals will hold their seats based on the current polling.

The real danger for Taylor isn't that colleagues fall in love with one of the alternatives. It's that they look at the calendar and decide they can't afford to keep waiting to make a change.

Taylor asked for the leadership because the Liberal Party was running out of time. He was right. That's now his problem.