On the afternoon of September 13, in Committee Room 1R2 at Parliament House in Canberra, a Powerpoint presentation was firing up.

Renegade Nationals MP George Christensen had invited a small group of his Coalition colleagues for a special presentation on the banks.

Among those in attendance, fellow backbenchers Llew O'Brien, Damian Drum, Ann Sudmalis and Craig Kelly. There was also a representative for both Ken O'Dowd and then-deputy PM Barnaby Joyce in the room.

Over the course of an hour or so, the politicians were methodically taken through a short history of banking behaviour since the Global Financial Crisis.

In particular, the practice of "constructive default", whereby everyday borrowers are forced into insolvency, often despite meeting their repayments, because the type of loans they signed before the GFC were seen by the banks as a liability after the crisis struck.

According to sources in Parliament, others, already convinced of the need for a royal commission were pleasantly surprised by the turnout at the meeting.

Perhaps enough Coalition MPs could be convinced, if it came to it, to team up with Labor and the Greens on the floor of Parliament to force a commission of inquiry into the banks.

By this week, that vague possibility had become a certainty.

With Mr Christensen and Mr O'Brien willing to cross the floor to support fellow Queenslander, senator Barry O'Sullivan's bill, an inquiry was going to happen one way or another.

As a result, we now have the Prime Minister's "regrettable" royal commission.

Nationals took advantage of Joyce's absence

Sorry, this video has expired Malcolm Turnbull announces a Royal Commission into the banking system ( David Lipson )

In hindsight, the writing has been on the wall for months. Certainly since the Government's numbers on the floor of Parliament were diminished by the dual-citizenship saga.

It must be bitter irony for the PM that some Nationals took advantage of Barnaby Joyce's absence from Parliament, himself a National who failed to get his citizenship paperwork in order, to help secure the numbers.

Then, after the Federal Nationals had shoved humble pie down Mr Turnbull's throat, putting his impotence up in lights, the New South Wales Nationals leader John Barilaro piled on, calling for the PM's resignation, because of "a Coalition Government in disarray". Bitter irony indeed.

The Nationals, it seems, have gone feral, as far as their relationship with the Liberals is concerned.

The Prime Minister could have owned the royal commission by seizing on one of the many banking scandals that have blown-up in recent months to declare, "enough".

Governments can be rewarded for backflips, when they're well executed on popular issues. It shows they're listening.

In August, 53,700 "serious and systemic" breaches of anti-money laundering and terrorism financing laws by the Commonwealth Bank were uncovered. Even that wasn't enough to convince Mr Turnbull of the need for an inquiry.

Is royal commission good for the nation?

Sorry, this video has expired Scott Morrison defends the government's changing position on the banking Royal Commission

Mr Turnbull's resistance (and ongoing reluctance) wasn't born out of stubbornness alone. It stems from a genuinely held fear that a no-holds-barred inquiry into the institutions that manage trillions of our hard earned dollars, could in itself undermine confidence and, hence, not be a good thing for this nation.

That's why the letter from the bank bosses asking for an inquiry was considered so important. It looked like a permission slip, as Bill Shorten claimed. But it's real aim was to mitigate stock losses for investors, spooked by the prospect of a loss of faith in the banks.

If the bank bosses themselves asked for an inquiry, surely it couldn't be too damaging.

What matters now is ensuring the inquiry delivers a positive outcome for the victims.

The Prime Minister was clear in stating the royal commission cannot deliver compensation for individual victims. It could, however, recommend the establishment of a compensation scheme, perhaps similar to the one set up by James Hardie for asbestos victims.

There are many who believed all along, only a royal commission can heal a sick, bonus-driven culture in the banks, that rewards profit, over and above the interests of customers.

Let's hope so.