Six candidates will contest the by-election for the South Australian seat of Bragg next month following the resignation of former deputy premier Vickie Chapman.
Independent candidate Neil Aitchison drew top spot on the ballot paper on Friday with Labor's Alice Rolls in second place and Liberal Jack Batty third.
The Greens, Liberal Democrats and Family first are also contesting the eastern suburbs seat which is likely to be retained by the Liberals despite a big swing against Ms Chapman at this year's state election.
She held Bragg with a margin of 16.6 per cent at the 2018 state poll, but that was cut to 8.2 per cent in March.
If the Liberals hold the seat, the opposition will have 16 in the 47-seat House of Assembly.
The Labor government holds power with 27 seats.
The Bragg by-election will be held on July 2 with pre-poll voting opening on Monday.
People in isolation or quarantine because of COVID-19 will be able to apply for a postal vote.
Special arrangements will also be put in place for anyone who contracts the virus after the June 30 cut-off for postal applications.
At polling booths, officials will be required to be fully vaccinated and wear masks with hygiene officers in place at each location.
At the March election, there were more than 25,000 people registered to vote in Bragg, which includes some of Adelaide's most affluent suburbs.
