Laws that prevent Australians from enrolling to vote in the weeks leading up to a federal election are set to be challenged in the High Court.
In a landmark case, activist group GetUp is pushing to have laws that suspend voter enrolment seven days after an election is called deemed unconstitutional.
The group says Australia's electoral laws have not kept pace with technology and are robbing hundreds of thousands of voters of their right to participate in the democratic process.
If successful, the case could see voters able to enrol as late as polling day – a practice that is now in place in NSW and Victorian elections.
In Queensland elections, voters can enrol up to the day before polling day.
The plaintiff in the case is Melbourne activist Tony Murphy, a GetUp member who recently lost a High Court battle to stop Melbourne's East-West Link from being built.
The legal team is being led by prominent QC and former federal court judge Ron Merkel.
A recent Auditor-General's report found more than a million eligible Australians are not enrolled to vote in federal elections and there is a "strong correlation" between age and enrolment, with just 61 per cent of 18 and 19-year-olds currently enrolled.
The report found just 68 per cent of Indigenous voters are enrolled to vote.
"That's more than a million people, including 100,000 Indigenous Australians, who politicians can forget about when they make decisions," GetUp democracy campaigns director Joshua Genner said.
"If we win in the High Court, someone who has just turned 18, a new citizen, or an Indigenous Australian who's never been enrolled would have much longer to enrol after an election's called and should even be able to go to a polling booth on election day, enrol and vote."
Polls consistently show that young voters are more likely to lean towards the left end of the political spectrum, suggesting a flood of late enrolments could benefit Labor and the Greens.
The case, which is being lodged on Friday, is not the first time GetUp activists have challenged Australia's electoral laws.
In 2010, two young GetUp members mounted a successful legal challenge to laws introduced by former prime minister John Howard that reduced the window people had to enrol to one day after an election was called, and to three days if they were changing their address.
"The two biggest states have now had elections with day-of-election enrolment and, by every measure, those elections have been better: more people have been enrolled, waiting times at polling booths have been unaffected, and the integrity of those elections has remained absolutely sound," Mr Genner said.
Mr Murphy said, "We are acting in the public interest, to encourage wider participation in the democratic process."
"This case is part of the democratic process. In our parliamentary democracy, the place where these sort of questions are resolved is the High Court," he said.