New laws enshrining truth in political advertising should be introduced to stop politicians lying with "impunity" and prevent division seeping into society, a parliamentary committee has been told.
A submission from UNSW professor George Williams to an inquiry into the May federal election calls for a crackdown on disinformation to strengthen the integrity of the electoral system and Australian democracy.
Prof Williams said a "narrowly drawn law for truth in political advertising" should be a priority for the parliament, which was failing to regulate its own "falsehoods".
"There must always be space for robust debate and to question even the most accepted orthodoxy,'' he said.
"It is also important that any new law cannot be weaponised during an election campaign by one party seeking court injunctions against its opponents."
Prof Williams said a lack of regulation meant "politicians can lie with impunity in the hope of misleading voters to secure electoral advantage", including scare campaigns involving Medicare and death taxes.
"When citizens cannot tell fact from fiction, and leaders spread falsehoods for political advantage, society as a whole is damaged," he wrote.
"The United States readily demonstrates this - Donald Trump's baseless claims about electoral fraud are sowing division and distrust throughout that nation and undermining good governance."
Prof Williams points to South Australia for a well-tested model, where since 1985 the state has banned electoral advertisements that set out statements of fact that are "inaccurate and misleading to a material extent".
A person can be fined $5000 and corporations $25,000, with the state's electoral commission able to request the removal of ads in breach, in addition to a public retraction.
Prof Williams said Australia's system of political finance law was broken and open to exploitation.
He urged that all donations to candidates and political parties be capped at $5000, as well as the real-time disclosure of donations more than $1000.
Prof Williams also suggested allowing 16- and 17-year-olds to initially vote on a voluntary basis.
"People under 18 can leave school, get a job, drive a car and pay taxes," he said.
"If the law permits them to undertake these activities, it is hard to see why they cannot also vote."
The inquiry will examine proposals for law reform on political donations, including real-time disclosure and a reduction to the disclosure threshold, as well as reforms to election funding.