A health educator and an Aboriginal community worker are vying to spring another by-election upset in a Liberal stronghold.
Labor will have another crack at winning a seat from the Liberals, with voters heading to the polls in the seat of Fadden on the Gold Coast on July 15.
The by-election was triggered by the resignation of former Liberal minister Stuart Robert, who has been mired in scandal.
Prime Minister Anthony Albanese will launch the campaign for Labor's pick Letitia Del Fabbro on Tuesday night.
He has described the nurse and health educator as a strong candidate, but acknowledged winning the seat would be tough.
The LNP holds Fadden by a margin of 10.6 per cent and has chosen Gold Coast councillor Cameron Caldwell as its candidate.
Opposition Leader Peter Dutton said by-elections were always "tight contests" and the Labor Party will have "all sorts of dirty tactics and smear campaigns" in its arsenal.
"We've got a great candidate with a good story to tell," he told reporters.
"I'm confident we can hold the seat, but by-elections are always difficult."
The Liberal Party lost the Victorian seat of Aston, previously held by Alan Tudge, to Labor in a shock defeat at an April by-election.
Indigenous-Aboriginal Party of Australia candidate Marnie Laree Davis is one of 13 candidates making a tilt for Fadden.
An Aboriginal community worker with a background in social health and domestic violence services, Ms Davis said she wanted to work with locals to deliver tangible outcomes.
Ms Davis said tackling the housing crisis, using preventative support measures to reduce crime, and accountability were high on her agenda.
"I am a proud Aboriginal woman, and decided to stand up and try have my voice heard for families and community," she told AAP.
Ms Davis said while the Indigenous voice to parliament proposal wasn't ideal, it was a "good stepping stone" to brokering a treaty with Aboriginal and Torres Strait Islander people.
The Greens, Pauline Hanson's One Nation and the Australian Democrats are also putting up candidates.
Mr Robert served as the veterans' affairs, national disability insurance scheme and government services minister under the Turnbull and Morrison governments.
