Katter and Wilkie's adorable pink pig onesies were in the finest tradition of political stunts and good on them for drawing attention to how Coles and Woolies are ripping off consumers. But let's talk about pork-barrelling - when governments and political parties have their snouts in the trough. Pork-barrelling is a folksy term that makes the act sound more benign than it really is: the misuse of public money.

Pork-barrelling is the all-too-common practice of governments and politicians allocating public funding to projects not based on need or the public interest, but on their electoral interests.

Former NSW premier Gladys Berejiklian infamously told the NSW Independent Commission Against Corruption it was more or less how things were done in politics. "I don't think it would be a surprise to anybody that we throw money at seats to keep them ... at the end of the day, whether we like it or not, that's democracy," she said.

It's not. Australia Institute research shows four in five (81 per cent) Australians consider it corrupt to allocate public money to projects in marginal seats to win votes.

Introducing her bill to the Parliament, Haines said: "We cannot accept this as a feature. It's a flaw in our democracy."

Robert Redlich AM KC, former commissioner of the Victorian Independent Broad-based Anti-corruption Commission, speaking at the Seabrook Chambers Public Lecture last year, agreed, saying: "The public considers pork-barrelling a serious breach of faith that is a form of corruption, in line with the NSW ICAC's finding that particular circumstances of pork-barrelling can constitute corruption."

Indeed, the NSW corruption watchdog found Berejiklian had engaged in serious corrupt conduct. The ICAC findings against her related to two government grants for organisations in the electorate of Daryl Maguire, with whom Berejiklian was in an undisclosed relationship at the time. ICAC also found Maguire acted corruptly and Berejiklian failed to report suspicions he had engaged in corrupt conduct.

While it's true Coles and Woolies have been ripping off Australians at the checkout, when it comes to pork-barrelling, Australians are effectively getting ripped off twice. The misuse of public funding is an economic rip-off because it wastes public money governments could spend elsewhere. There's also an electoral rip-off because it undermines our trust in government and shortchanges our democracy.

Governments are elected to govern in the national interest, not their own electoral interests. Australia Institute research shows Australians adopt a definition of corruption that goes beyond criminal conduct, including giving jobs to mates, pork-barrelling, constraining integrity bodies and using appointment powers to remove political rivals.

The former federal Coalition government was exposed by the media for multiple examples of the misuse of public funding in the awarding of grants. In the sports rorts scandal, the then-Nationals minister Bridget McKenzie's office used a spreadsheet - blatantly colour-coded by which political party held each seat - to override official advice and award community grants to marginal seats targeted by the Coalition.

The $660 million car park rorts scandal was an even bigger rip-off. Not a single commuter car park site was selected by the department based on the need to solve congestion issues, the stated aim of the program. Instead, each grant was handpicked by the Coalition to serve its own ends at taxpayers' expense. Just this week, an audit report found a $5 billion fund for Western Sydney projects designed by the former state Coalition government in NSW "lacked integrity". Five. Billion. Dollars.

But pork-barrelling isn't unique to one side of politics. This perennial problem has been difficult to tackle because what enrages political parties in opposition quickly becomes a perk when in government.

Haines' bill aims to prevent this misuse of public money. Her bill does four things: it requires merit-based selection criteria and guidelines that are publicly available, it requires a minister to report to Parliament when they have ignored official advice, it establishes a new joint parliamentary committee to oversee compliance and administration of grants, and it requires the minister to report to Parliament whether various public funds (such as the Housing Australia Future Fund) are complying with their investment mandates.

Presumably, the maladministration of billion-dollar Commonwealth grants programs is also the kind of serious corruption the new National Anti-Corruption Commission will investigate. Sadly, the public may never know because, unlike the extremely successful NSW ICAC, the national corruption watchdog's hearings are held in private unless there are exceptional circumstances.

This makes Haines' idea for a joint parliamentary committee to publicly scrutinise grants administration a necessary one. Over the past few years, we have seen Labor senator Deb O'Neill and Greens senator Barbara Pocock effectively use Senate committee inquiries to publicly and forensically scrutinise and hold to account the big consulting firms after the PwC scandal. Corruption thrives in the dark. Sunlight is the best disinfectant and public scrutiny not only brings these issues into the spotlight, it helps restore the public's confidence in our democratic systems, a precious resource that serious and systemic corruption erodes over time.

Let's not put lipstick on a pig: pork-barrelling is a flaw of our democracy, not a feature. The public is sick of scandals involving the misuse of public money. But unless we make it clear it is unacceptable, it will become business as usual. Preventing pork-barrelling can only benefit political parties and Australia's democracy in the long term.