The onslaught has begun.

The television ads are in overdrive, the tame media commentators are barking and even the bankers themselves are putting on a parade, gracing as they did the stage at a "summit" last Thursday.

And all within a week since rumblings from Coalition members threatening a private members bill to bring on a royal commission into banking.

Those bloated profits from our financial institutions, they benefit all of us, we're told in soothing tones by reassuringly ordinary looking Aussies staring benignly from our television screens because, let's face it, we all own bank shares through our superannuation.

It's always handy to throw in a few threats for good measure.

As for a royal commission, well, if you believe the bankers, the real losers will be you and me because it will push interest rates higher.

Others claim, it's all a conspiracy theory, whipped up by populists for cheap political gain.

There was even a dismissive jibe that a full inquiry would serve no purpose because it would only dredge up things that have already happened, which is sort of the entire point of an inquiry.

But in all the noise being generated by their strident opposition, one question remains unanswered: What exactly is there to hide?

Quite a lot it would seem, judging by recent events.

The calls for a full inquiry have been relentless for years, emanating from a broad section of the community — from farmers, small business and households, jaded and disillusioned with the industry's rampant profiteering, fee gouging and blatant disregard for the law.

How many times can a Commonwealth Bank chairman sincerely apologise for a yet another breach of trust? What, pray tell, will be the cause of next year's?

But the overwhelming reason for an inquiry rests on just one principle — accountability.

What has been forgotten in the endless round of scandals in recent years is that the Australian banking sector is a taxpayer subsidised industry.

It's an industry that pays ridiculously bloated salaries to its leaders; that showers itself with massive bonus payments when profits are soaring but instantly demands taxpayer protection and support when the tide turns. More on that later.

One scandal after another

Let's backtrack just a little and examine our local industry's record on scandals.

Deutsche Bank analyst Mike Mangan, who now runs boutique funds manager 2MG, has compiled a neat summary of banks' transgressions during the past decade. It includes everything from the Storm financial crisis to rigging the Malaysian currency markets and providing bad financial advice.

Since the financial crisis, Australian banks have forked out more than $1 billion in fines and compensation from rorting their own clients.

There are a couple of observations to be made here.

The first is that, given our corporate regulator is notoriously slack at pursuing corporate malfeasance, the fines quite possibly are hugely light on.

And the second is that, despite that, no other industry in history has been so dogged in the pursuit of profit with such flagrant disregard for its customers and the community.

You're busted. A brief history of bank fines ($A million)

Mr Mangan hasn't limited his research to Australia. And this is where the horror becomes truly apparent.

Difficult though it may be to believe, Australian banks are among the world's best behaved, at least if you base it on total fines paid.

The Commonwealth Bank will be put under a microscope in a royal commission. ( ABC News: Margaret Burin )

In the US, banks have forked out more than $206 billion in fines in the past decade, a further $116 billion in the UK and $76 billion in Europe.

Right now, however, there are three significant Australian cases either looming or before the courts.

The CBA's 55,000 breaches of terrorism financing and money laundering laws has attracted the most heat.

Then there is ASIC's case against Westpac over the alleged rigging of the domestic interest rate market which already has begun to shine a light on the inner workings of modern banking (ANZ and NAB ran up the white flag on that one).

But it is the recent sacking of more than 20 National Australia Bank employees and looming court action that has the potential to get to the heart of one of the economy's major flash-points; how our banks have helped artificially inflate the property market by aggressively pushing loans on to customers.

How the banks support democracy and avoid scrutiny

It should come as no surprise that our finance industry is a major political donor.

An ABC study early this year noted that finance and insurance interests donated $2.69 million to both major political parties last year, which skewed towards the Coalition but still delivered more than a $1 million to Labor.

That money doesn't come without strings. Despite the litany of offences over the years, both sides of politics have been more than happy, until recently, to run to the defence of our financiers.

Labor took a royal commission to the last election but only after a great deal of internal debate.

The Turnbull Government, meanwhile, has been resolute in its stance to avoid a formal inquiry but has been forced ever closer.

It's insisted on regular appearances of four main banking chiefs before parliamentary inquiries and supported greater oversight by regulators, including measures to restrict pay.

Now, with Liberal National Party Senator Barry O'Sullivan threatening to lob a motion to the Senate as early as this week, the gloves are off.

Senior Coalition members are terrified, having been forced for so long to walk the tightrope between hauling bankers into line and staunchly opposing an inquiry.

If the motion gets up, it would be a major loss of face for Mr Turnbull and the Government, with serious ramifications for his grip on leadership.

In a show of desperation, the banks have opted to go straight to the public, the area where they possibly have the least support, with a multi-million dollar propaganda campaign on free to air television and newspapers. And the fight is likely to get ugly.

Liberal National Party Senator Barry O'Sullivan has threatened to lob a motion to the Senate. ( AAP: Dave Hunt )

The great Australian bank subsidy

Former prime minister John Howard weighed in last week, warning government members that any inquiry would be "rank socialism".

It was an odd choice of words. Our banks and financiers have been happy recipients of state sponsored socialism for the past decade.

Prior to the financial crisis, there was an understanding the Reserve Bank would stand behind any bank in trouble as a lender of last resort.

As the crisis took hold, however, almost every Australian commercial bank was in danger of collapse because they could no longer refinance their debts.

The Rudd government stepped in, guaranteeing all new borrowing by allowing the banks to use the Commonwealth's AAA credit rating.

As a result, taxpayers delivered a $120 billion bailout to our banking system as the banks refinanced their international loans.

Sorry, this video has expired Opposition Leader Bill Shorten calls for royal commission into financial services sector

It was the greatest industry subsidy in our history. And it continues.

That once implicit guarantee for individual organisations became an explicit guarantee for the entire industry, forever changing the relationship.

It's a guarantee the Reserve Bank has calculated to be worth about $5 billion a year to our big four banks.

It didn't stop there. Short selling of financial stocks was banned temporarily, following furious lobbying, particularly by Macquarie Bank.

As an added bonus, the Rudd government guaranteed deposits up to $1 million in an effort to stop any run on the banks.

Those guarantees have remained in place ever since although the deposit guarantee has been wound back to $250,000.

They are an insurance policy — delivered free of charge courtesy of the taxpayer — that the banks have happily accepted ever since. Not that there has been any gratitude.

When Treasurer Scott Morrison announced a bank levy on bank transactions in the May Budget, the outcry from the banking sector was deafening.

Once upon a time, this type of behaviour was laughingly referred to as agrarian socialism — maximise your profits and socialise your losses — because it largely was confined to the rural sector.

There's a certain irony that it took an LNP Senator to call out the big end of town.