When a customer walks into a shop, they can be confident that Australian consumer law bars that business from engaging in misleading and deceptive conduct. Advertising must not "bait" customers with low prices for stock that is only in limited supply, make a prominent discount offer then hide the terms and conditions behind packaging, or lie by omission.

Australians should be entitled to expect the same standard of honesty in politics as they receive in trade and commerce - if not a higher standard. But across most of Australia, including in the ACT, it is perfectly legal to lie in a political ad.

Voters have a right to make informed decisions, and misleading and deceptive political advertising undermines that right. Ultimately, none of us benefit from lying politicians - not even the politicians themselves, who overwhelmingly run for office in order to do good, and who suffer worst of all from the poor reputations that politicians can have.

Recent elections - particularly at the federal level - have seen warring claims of lies, fake news and untruths across the political spectrum. Misleading advertising undermines confidence in the political process. When one side feels like it has been subjected to false claims, the temptation grows to respond in kind. With trust in government and parliament already at a low ebb - though the pandemic seems to have inspired somewhat of a restoration - something needs to be done to arrest this vicious cycle.

The Australia Institute's research shows that the public wants truth in political advertising. Polls conducted over the last four years show consistent, overwhelming support from voters from all political parties. Our most recent national poll shows nine in 10 Australians support truth in political advertising.

As well as popular support, the push has been endorsed by prominent Australians from legal, political, academic and civil society backgrounds. This week, 15 prominent Australians wrote to the Legislative Assembly calling for truth in political advertising laws in the ACT. Among their number are former judges Anthony Whealy and David Harper, former NSW Director of Public Prosecutions Nicholas Cowdery, and former politicians Dr John Hewson, Cheryl Kernot and former ACT MP John Langmore, who represented the seat of Fraser (now Fenner) for 12 years. Academia and civil society are also represented.

The movement towards truth in political advertising in the ACT has been kickstarted by Greens MLA Caroline Le Couteur, but the issue is a non-partisan one and has broad support. The call for truth in political advertising laws at the federal level has also come from Labor statesmen Jay Weatherill and Craig Emerson in their review of the 2019 federal election, Independent MP Zali Steggall and Liberal MP Jason Falinski.

The ACT has an opportunity to clean up its own act, but also serve as an example for the rest of the nation. As the heart of Australia's democracy, we can set a precedent that spurs federal politicians and their peers in other states and territories to follow our lead. It would not be the first time that the ACT has served as a laboratory of democracy; Australia Institute research shows that a stamp duty to land tax swap and reverse auctions for renewable energy have received interest around Australia following their adoption in the ACT.

Fortunately, in this case the ACT has its own example to follow. South Australia has had truth in political advertising laws since 1985, providing abundant proof that these laws can be constitutional, enforceable and respected. The Electoral Commission serves as an independent umpire for complaints, and their requests for withdrawals and retractions are almost always respected.

Of course, Canberra's public and its politicians should be prepared to debate how we want truth in political advertising laws implemented, and decide on a unique model if that is preferred.

Questions of regulating speech raise reasonable concerns around freedom of speech and political communication. With the Australian Constitution's implied freedom of political communication, preserving freedom of speech is a legal requirement of these laws as well as a moral necessity.

Fortunately, the High Court has long held that there is no right to "disseminate false or misleading material" (Justice Gaudron in Australian Capital Television), meaning that truth in political advertising laws need not fall afoul of the Constitution.

Truth in political advertising laws do not control opinion - even strident, callous or vicious opinion. They will not, by themselves, mean the end of the attack ad or the slur. However, they can help ensure that voters are not lied to or given inaccurate material; armed with the facts, voters will have to decide for themselves which opinions to take into consideration.

The greatest strength of truth in political advertising laws is not in the misleading ads that they punish, but in the change in culture that they can achieve. Ideally, these laws will never be used once they are in place - because politicians and third parties will respect the truth and obey the law.

These laws are an opportunity to flag a change in our political culture and make truth telling the done thing.

With almost three months to run until the territory election, there is still time to pass truth in political advertising laws here in the ACT. Such laws would not solve all our ills, but they would help ensure that voters can spend their time weighing the facts and arguments instead of sorting fact from fiction. Or worse, switching off from the debate altogether. While territory-level laws would not by themselves clean up federal politics, they would set a strong example in the heart of Australian democracy.