Treasurer Scott Morrison taking a lump of coal onto the floor of Parliament was just as much about the tensions simmering within the government as the other surprises that occurred this week.

One such event was Malcolm Turnbull’s attack on Bill Shorten.

Smack-down speeches like the PM’s castigation of his counterpart tend not to materialise out of nowhere. For example, PM Julia Gillard’s “misogyny speech” was based on a list of quotes by Opposition Leader Tony Abbott that Ms Gillard kept on hand for easy reference. When Mr Abbott put pressure on her over the speaker at the time, Peter Slipper, she pulled out the note and deployed its contents with devastating effect.

The Canberra press gallery at the time saw a PM under pressure lashing out at her most obvious opponent, but Ms Gillard’s performance was more about rallying government backbenchers and Labor voters than it was about tarring Mr Abbott with the misogyny brush.

It’s a similar story this time; Mr Turnbull appears to have had enough of the class war that Labor’s been waging against him and retaliated this week by labelling Labor leader Bill Shorten a fake, a hypocrite and a “social-climbing sycophant” for provoking class envy when he has a history of hobnobbing with the business elite.

Mr Turnbull appears to have also based his tirade on notes, in this case furnished by Defence Industry Minister Christopher Pyne. But no matter whether they were scribed in stone or scribbled on the back of a beer coaster, we can be assured the taunts were crafted to resonate with soft Labor supporters and undecided voters who are expressing similar sentiments about the Opposition Leader in opinion poll focus groups.

The fiery performance was also to show disheartened and disgruntled government backbenchers that there’s no need to be pondering yet another change at the top of the Liberal Party.

Conservative Liberals in particular would be unsettled by events this week, with Cory Bernardi demonstrating how a man truly committed to his espoused principles should be willing to walk away from the trappings of government in order to uphold those principles.

While some of the conservatives castigated Senator Bernardi for the move, others blamed the PM for not doing enough to keep him in the tent, adding this deficiency to the long list of reasons why Mr Turnbull should not be Liberal leader.

However, even if leadership rumbling crystallises into action, the manoeuvring of younger conservatives this week suggest a spill may not necessarily herald the return of Tony Abbott.

Immigration Minister Peter Dutton fancies himself as Mr Abbott’s heir apparent should Liberal MPs conclude they can’t retain government with Mr Turnbull at the helm. So it was no surprise to see him sitting with the former PM at a joint party room meeting earlier this week.

Peter Dutton is emerging is a potential Liberal leader, but he’ll have Scott ‘Coal’ Morrison to contend with. Photo: AAP

Mr Dutton holds the perfect portfolio to endear himself to conservative MPs (and voters), and is prepared to make Trump-like sounds to prove can do whatever it takes to compete for One Nation votes.

But the Immigration Minister will face an even tougher fight for the Liberal leadership.

That’s where Treasurer Scott Morrison’s pet rock comes into play.

It is perhaps not a coincidence that around the same time it is revealed that the PM’s new climate adviser has been recruited from mining lobby group the Minerals Council of Australia*, a lump of coal reportedly provided by the MCA is brandished by the Treasurer in the Parliament.

Urging the Labor frontbencher opposite him not to be afraid of the lacquered chunk, which had been “dug up by men and women who work and live in the electorates of those who sit opposite,” the Treasurer sang the virtues of coal-fired electricity as part of the government’s latest campaign to link Labor with high electricity prices and associated job losses.

Onlookers may have been puzzled to see the coal passed along the government’s frontbench and then among its backbenchers (in direct contravention of the parliamentary rule against the use of props), but the purpose of the Treasurer’s behaviour was clear.

Mr Morrison set out to prove to agitating Liberal conservatives that, if there’s going to be a change of Liberal leader, he is the man to take the fight to Labor on totemic conservative issues such as coal-based electricity.

* Paula Matthewson, former media advisor to John Howard, once worked for the Minerals Council of Australia and the Australian Coal Association, and currently has clients in the renewable energy industry.