It refers to the final sitting week for a parliamentary sitting, when MPs sometimes decide to change leaders before leaving Canberra for several weeks.

Kevin Rudd took over from Kim Beazley before the summer break in 2006. Julia Gillard rolled Rudd in June 2010, on the eve of the winter break. Tony Abbott defeated Malcolm Turnbull in December 2009.

The reason for changing leaders is nervousness over the state of the polls. This rises to panic when an election is due the following year.

The MPs chatter in the fervid atmosphere of Parliament, striding down the long corridors to consult with equally nervous colleagues.

This weekend MPs are back in their electorates, with the House having sat for only two weeks in October. They return later this month for the final sitting year of the year - the killer week.

It will be marked by fun and frivolity as political leaders host Christmas drinks but beneath this early bout of festivities, both sides will barely be able to conceal their hope that the other mob is about to do over their leader.

That underlying tension accounts for the numerous personal barbs and taunts thrown across the chamber in the past few days. But a reality check is due - at this stage, both major parties look set to keep their leaders.

Labor's steady rise in the polls means Rudd can't make a comeback if the trend continues. The recovery has been faster than many anticipated, with Newspoll indicating the two party preferred vote is now 50-50.

Rudd has promised not to challenge again. The last one did Labor enough damage to last a term. And Gillard outsmarted him by calling on the ballot.

Now Rudd realises his only option is to say, privately, he would only agree to be drafted. That is, Gillard would have to willingly step aside and hand him the prize. And pink pigs might fly.

Gillard is as tough as nails and has devoted her life to politics. She would not step down willingly and there is no pressure to do so at the moment.

Her tragic days are behind her. At least, that's what her supporters say. They desperately hope for no more misjudgments.

Nevertheless, Rudd has been lifting his public profile in recent months, notably when the PM is overseas. The release of Maxine McKew's book, Tales from the Political Trenches, with its belated indictment of Gillard, fits with the timing of a possible build-up in his momentum to the last week of Parliament, just in case the polls were low and grumbling was high.

McKew defeated John Howard in Bennelong but lasted only one term. In her book she argues Gillard had greater involvement in the 2010 coup to topple her (McKew's) hero than Gillard has admitted.

McKew details a meeting at Kirribilli House in January 2009 where Gillard apparently delivered ''a blunt message'' - the deputy Prime Minister would not support an election based on the need for climate change.

''Gillard never relented and throughout the early months of 2010 continued to pressure Rudd to abandon the [emissions trading scheme],'' McKew says.

When he finally did drop it like a hot potato, the decision poleaxed his support in the polls and led directly to his demise.

''I do not believe Gillard can be seen as a passive player,'' McKew writes. ''She was impatient for the prime ministership and allowed others to create a sense of crisis around Rudd's leadership. She then cut down a Prime Minister in his first term and pretended it was in the national interest to do so. The voting public saw it for what it was: a brutal grab for power. And they've never forgotten it.''

McKew concedes that Rudd has his faults but is scathing of the belated character assassination given about him by ministers earlier this year, to undermine his leadership challenge.

''Gillard's backers, however, have been masterful in the way they have cemented a particular narrative about Rudd's deficiencies as a leader'', McKew says.

The former ABC journalist delivers a compelling narrative but it is too late for this one-eyed account to sway caucus.

If it had come a few months ago, when Labor's support was truly dismal, it might have had a greater impact, possibly even tipping the balance.

Now Gillard has her confidence back. She is striking back hard at Abbott in question time and kicking goals, for instance the breakthrough on pokies.

She's convinced the Greens to accept the watered-down reforms and Andrew Wilkie is following suit, despite Gillard breaking an earlier promise to him on pokies when it looked like she didn't need his vote following Peter Slipper's resignation from the Liberal Party.

The PM has created a flurry of activity with her Australia in the Asian Century white paper and its focus on education, one of her passions. But life is not without challenges and problems for the Prime Minister.

Locking herself into the promise of delivering a surplus this financial year is causing huge problems. This is emerging in changed language since the delivery of the mid-year budget update.

The promise to deliver a surplus has become a determination, a plan, which is ''on track''. As a commitment, that's about as firm as jelly. Gillard's problem is that the budget is being squeezed by the fall in revenue from resource exports and company tax. And the boats just keep coming and, as a result, the bill for processing asylum seekers just keeps mounting.

The figment of making Australia disappear from the migration zone is not going to deter anyone from making the hazardous journey if they had already planned on a long stay at Nauru or PNG, in preference to staying in a civil war.

As Labor's support rises, and Gillard's grip on the leadership firms, ministers are now trying to distract from the government's leadership situation by putting the spotlight on Abbott.

They like to needle the Opposition Leader with a reminder that he won his job by just one vote in the contest with Turnbull. So what?

Since then Abbott's high-intensity, marathon campaign against that broken promise on the carbon tax has plunged Gillard's credibility rating to subterranean levels, and that drove Rudd to challenge for his old job.

On the flipside, Abbott overreached on the carbon tax. Its implementation was not a catastrophe. And, after Gillard called him a misogynist, he has been punished in the polls for a perception of aggression towards women.

Former Speaker Peter Slipper joined in the chase this week, saying the Coalition voted against wheat deregulation to preserve the ''flawed and fatal and terminal leadership'' of the Leader of the Opposition.

As Parliament wound down on Thursday, ending its penultimate sitting week for the year, Climate Change Minister Greg Combet worked the crowd, enlivening his Labor buddies with a play on the Melbourne Cup in which Turnbull was ''a classy thoroughbred if ever there's been one'' and Joe Hockey was ''hungry for a win''.

However a Liberal moderate, no great fan of Abbott, put the private view yesterday the Opposition Leader's job appears safe.

Both leaders will be much happier when the final week of Parliament is behind them.

Ross Peake is Political Editor.

twitter: @rosspeakeCT