Should Turnbull be resurrected as leader, and perhaps a majority of Liberals are now willing it so, it will have been more than five years since the urbane Sydney millionaire was explosively ousted from the leadership by the grittier, more conservative Abbott – a win that came by way of a razor-thin majority of 42 votes to 41 in a bruising second-round ballot that had earlier dispatched Joe Hockey.

Support for the other possible leadership contenders, principally deputy Liberal leader and Foreign Minister Julie Bishop, and Social Services Minister Scott Morrison, appeared to wane as the week progressed.

Unmistakably, Turnbull remains a peoples' favourite, being consistently preferred by voters through a succession of opinion polls.

Which is why desperate Liberals argue the green-tinged former businessman offers the best, indeed only, chance of recovering the middle-ground support squandered by Abbott.

"We need a leader who speaks to the whole country, not just to Alan Jones and Ray Hadley," one enthusiast said.

Yet even advocates of Turnbull's re-elevation know it would come at a terrible cost, necessitating the knifing of a sitting first term prime minister – reprising Labor's tumultuous hatchet-jobs on Rudd in 2010 and Gillard in 2013. And, there's the aftermath.

Could Turnbull reunite the party?

Could Turnbull unite his party again after such an assault and restore its equilibrium? Would the Right ever truly back him? And what of the ousted Abbott and other victims such as Treasurer Joe Hockey, Kevin Andrews, Peter Dutton, and Eric Abetz – would they just disappear?

These are the considerations ricocheting around an increasingly depressed government as MPs file into the capital from Sunday, for what may be one of the truly historic weeks in the political life of this nation.

"I'm depressed," said one minister, as he acknowledged the "probably unstoppable" process now underway and likely to result in a spill motion on Tuesday.

But confusion surrounds the precise mechanics governing any resolution.

Some told Fairfax Media that a successful spill motion – one that attracts more than half of the 102-strong party-room – would be tantamount to a vote of no-confidence in Abbott, and that he would bow out of the race at that point. That would free others to put their names forward, released from any promise not to challenge.

Another MP claimed a spill motion is rarely put to a vote anyway, with leaders in the past observing the unwritten convention that if a sizeable chunk of the party-room wants a spill, it is granted.

"Only a weak leader would try to hang on merely through some technicality," said an MP, who claimed a neutral position.

"This is not what we came here to do," said an exasperated backbencher, who went on to describe his emotions as "resignation tinged with real anger" at the damage done by internal power struggles.

"This is not a game," he said.

Those sentiments were echoed by Trade Minister Andrew Robb who urged his colleagues on Thursday, not to behave like "kids".

"If something happened on Tuesday, which led to a spill, we would be seen as a bunch of amateurs," he told Sky News.

Yet, even he acknowledged that the government had brought the trouble on itself with unexplained policies and unpleasant surprises.

"People are looking to the government for stability, they want peace of mind from the government and I think we've contributed in part," he said.

"We've given our opponents a free kick, we've allowed them to misrepresent and frighten people about our program when that is not our intention whatsoever, and I think we've just got to be smarter this year about how we execute policy, about how we introduce new policy how we explain it, carry people with us and therefore, make sure that we've got a more stable political environment."

Near frontal attack

It was as close to a frontal attack on the political strategising capability of the prime minister's office as a supporter could be without crossing over.

Robb has himself been mentioned as a potential deputy leadership candidate or treasurer. One Liberal suggested his promotion could be a condition of agreeing on Turnbull as Abbott's replacement.

But, like every other cabinet minister when asked, Robb was locked in behind Abbott at week's end.

So too Hockey, who's obvious frustration at the galloping chaos rose with each reported development.

"Stop engaging in commentary on colleagues, stop engaging in commentary on the leadership, focus on fixing the country," he implored his confreres.

That brought a withering response from one equally frustrated MP, who quipped privately to Fairfax Media that "fixing the country would have been a lot easier if Joe's budget hadn't f--ked the government".

The cleavage in the Liberal Party in the first weeks of 2015 is extraordinary when viewed against the unity and internal discipline since Abbott took over in 2009. Despite his one-vote majority, Abbott brought his riven party together in double-quick time and took it to within a whisker of victory just nine months later.

It was a stand-out performance, which his party rewarded through its continued support for him through to the 2013 poll that he won handsomely.

Abbott had defied a tendency of parties to burn defeated opposition leaders after each election.

But the story of Abbott's leadership once in office is one of steady then rapid decline.

A series of politically "courageous" policy decisions, many of them clear broken promises, strained internal cohesion by exposing MPs to attack by the opposition on the key indices of fairness and honesty.

As 2014 wound to a messy close, Abbott partially – and tacitly – acknowledged his problems by promising to clear away his biggest policy problems. But when it came it was jumbled, incomplete, and accompanied by the boast that 2014 had been a great year for the government.

Barnacle clearing became a barnacle

The barnacle clearing that was supposed to have facilitated a fresh start in 2015, itself became a barnacle, leading to a January from hell for Abbott.

And February would start out even worse, beginning with emphatic repudiation of the first-term LNP government of Campbell Newman, in Queensland.

Queensland LNP members at both state and national levels, were livid, saying federal factors overwhelmed their message and trashed their brand.

They listed discussion of changes to the GST in the first weeks of the campaign, the unheralded backdown on the Medicare short consultation rebate days later, and finally, of course, the spectacularly stupid knighting of Prince Philip just three days before the election.

"We became a laughing stock," one Queenslander said.

"He hasn't just got a tin ear," quipped a Canberra insider of the Prime Minister, "he's got a tin head!"

By Monday, the pressure on Abbott to use a National Press Club address to pull off an unlikely reboot of his 2015 agenda was intense. Right on cue, the first of the monthly Fairfax-Ipsos polls for the year confirmed his standing had suffered a massive deterioration over summer from an approval rating of minus-19 to minus-38.

Voters were deserting in droves and it appeared it was Abbott himself that was causing the exodus.

At last he moved decisively, dumping his signature paid parental leave scheme. He also palmed off responsibility for future Australian knighthoods to a committee, flagged a new families package with increased and simplified childcare funding, promised small business tax relief, tougher anti-terrorism laws, and promised to lead the most consultative and collegial government the country has ever known.

It was a solid, if belated pivot into which supporters read real change, and detractors poured scorn.

Before the day was out two Queensland colleagues had made clear their response. Andrew Laming declared his intention to have parliament abolish the knights and dames rank entirely and he was quickly backed by another, Warren Entsch.

While MPs had been backgrounding Press Gallery journalists for weeks about their concerns over Abbott's political judgment, the combination of the polls, the backflips, the Queensland result, and the knighthood, had coalesced. And suddenly, people were putting their names to things. Defiance of Abbott was coming out into the open.

Others were to follow such as WA's Dennis Jensen. At that point, the voices could be dismissed as the usual renegades, but then the erstwhile Abbott loyalist Arthur Sinodinos dropped a bombshell on Wednesday, revealing his deep concerns, and that his support was ongoing but not unconditional.

'Comrade, ask next week'

Asked by David Speers, if Abbott would remain prime minister, he responded "Comrade, ask me next week."

Despite his fall from the ministry Sinodinos remains a respected strategist and an authoritative voice having served as a successful chief of staff to John Howard.

Abbott's support was in danger of evaporation.

The day before, Bishop had waited all day to respond to an ultimatum from Industry and Science Minister Ian Macfarlane, that she publicly commit to Abbott and forswear any challenge. It came in a tense Cabinet exchange that was quickly briefed out.

Bishop was furious that her loyalty was questioned, and railed against having to respond to a hypothetical.

On Wednesday morning, Abbott met with Turnbull. What was discussed is disputed but Fairfax Media has been told the meeting had been arranged weeks before and that no undertaking regarding a challenge was either sought or offered.

By Friday, events were gathering pace. Christopher Pyne was asked by Karl Stefanovic on Nine's breakfast program if Abbott still had the numbers.

"That's a very inexact science, I hope he does, yes," he responded.

"Will he be prime minister next Wednesday?" pressed Stefanovic.

"Well, I certainly hope so".

The former minister Sharman Stone added her name to the list of MPs advocating change, with the regional Victorian telling her local ABC on Friday, "The public's giving me loud and clear messages, they do want to see a change".

Abbott supporters know the danger will peak, however, when the colleagues are gathered together in the same building.

That's when discussions will start in earnest and events could move very fast indeed.

An MP known for wisdom in these matters could only mimic Sinodinos when asked on Thursday how it will play.

"Comrade, ask me next week," he said, half cheerily.