On the face of it the behaviour of the former shadow parliamentary secretary undermines public confidence and appears to be using public office for private purposes. The Herald chooses those words carefully because they are taken from the Howard government's ministerial code of conduct. The standards a government sets for itself are crucial. The Howard government set the bar high and lost seven ministers in its first two years for betraying voter trust. Four of those cases involved expenses claims.

In the first six weeks of the Abbott government, the public has learnt that while in opposition Coalition MPs claimed for weddings, sporting events, large libraries, book tours and now, thanks to Mr Randall, about $2500 on books covering topics such as Broadway musicals, children's cooking, animals and rock'n'roll. It is hardly reassuring that Mr Randall is on the parliamentary privileges committee. He also refused to respond to a series of questions from Fairfax Media. Every MP has a duty to be open and honest with the community. In fact, the expenses system relies on honesty and trust. MPs simply self-report their expenses and repay money when an error is found or, more often, when the embarrassing truth is revealed.

Indeed, Mr Abbott has been forced to repay some expenses but refuses to hand back others. That would be forgivable if taxpayers could trust those who are meant to follow the rules to apply some commonsense. They cannot. The average person regards the words “parliamentary, electorate or official business” as pretty clear. MPs, on the other hand, find excuses such as “everybody does it”, “we have to work 24/7” and “it's a grey area” to make their expenses claims fit the rule.

And Mr Abbott's response? He refuses to reform the system. “We don't want to fixate on this,” he says. “You don't want members of Parliament to be prisoners of their offices.” This approach is hardly reassuring. Recall that Mr Howard's 1998 behaviour code said ministers “should ensure that their conduct is defensible, and should consult the Prime Minister when in doubt about the propriety of any course of action”. Labor MPs have also been exposed on expenses, so the Parliament in unlikely to fix anything unless a disgusted public forces the Prime Minister to act.

Without leadership from Mr Abbott, the rorting problem will not be solved and the issue will continue to detract from any good work his government is doing. Today the Herald restates its demand that the government establish an independent integrity commission to oversee rewritten rules on expenses. They should require prior approval and place the onus on MPs to prove compliance. Loading Mr Abbott also needs to fast-track completion of a new code of conduct for all his MPs then enforce it. Preferably, all parties would accept the code. But in the meantime, the Prime Minister should force out any member of his team who regards expense fiddling as a right and treats voters with such disdain.