Look what happened to Bronwyn Bishop. The former federal speaker initially dismissed the furore over a decision to charter a chopper to a Liberal fundraiser as a "political beat-up".

The court of public opinion begged to differ.

Two-and-a-half weeks later, Bishop was forced to relinquish her privileged position, having inflicted massive damage on the Coalition in her attempt to withstand a tsunami of public opinion crashing against her.

Similarly, state minister Steve Herbert's attempt last year to cling on to his post after being caught out using his parliamentary car to ferry his dogs around turned a bad situation into a diabolical one.

Victorian lower house speaker Telmo Languiller's decision to repay almost $40,000 after claiming a "second residence" allowance to live miles from his electorate in Queenscliff is, albeit belatedly, the right thing to do.

His speedy act of contrition also represents an attempt to cauterise the wound to avoid the political equivalent of gangrene.

The tendency for politicians is to cling on to the notion that they acted – technically – within the rules. But those rules are so sketchy they do our political representatives no favours, because they allow behaviour which is ethically wrong.

Mr Languiller himself seemed to acknowledge this on his way into Parliament on Thursday morning, saying the system "allowed" him to make the claim.

"On reflection I believe the system which allowed me or others to make a claim of [that] kind should be changed," he said.

I think he is right. The rules should be tightened to the point where they are precise, detailed and transparently administered. Others disagree.

Running the gauntlet past journalists on his way into parliament, Treasurer Tim Pallas said a change to rules was not the answer, but rather MPs should be guided by "common sense".

"I don't believe it is a question of rules, it's a question of people understanding what the right thing to do is," Mr Pallas said.

"Quite frankly, there's always a way around rules ... but there is no way around holding yourself to account to good conduct and the public expectation."

This is true. MPs should be guided by commonsense. Trouble is, all too often they aren't and then run into strife. Which is exactly why the rules need to be changed.

In the case of Mr Languiller, the situation is even more complicated because, as speaker, it is part of his role to uphold the highest standards of the parliament.

He also plays a big part in the self-regulation of the very system that "allowed" him to make the claim.

It needs to be independently administered, and those found to have breached the rules should be treated in the same way as any member of the public caught rorting the system, whether tax, social security, the banking system, or their workplace.

Whether Mr Languiller will now survive is a bit unclear.

He has helped his case by immediately agreeing to repay the money and admitting the claims "does not meet community expectations", but only after he was caught out.

He also added that "complex family matters relating to marriage, children, parents" led him to rent a property in Queenscliff.

That may be so, but there are still some outstanding questions, including how much time he actually spent in Queenscliff, why he stopped claiming the allowance in November last year, and when he told the parliament that his official residence had changed from Queenscliff to Footscray.