Candidates hoping to replace Malcolm Turnbull in the former prime minister's Sydney seat are set to be announced.
The Australian Electoral Commission will declare all nominations for the October 20 Wentworth by-election at midday on Friday.
There are 13 candidates who have publicly put their hand up in the contest for the eastern Sydney seat which the Liberal Party has never lost.
A loss for the Liberal party in Wentworth will mean the end of the Morrison government's one-seat majority.
Liberal candidate Dave Sharma is expected to reveal how he wishes voters to direct preferences in coming days, after saying he would wait until the final list was sorted.
High-profile independent candidate and local doctor Kerryn Phelps poses one of the biggest threats to Mr Sharma, Australia's previous ambassador to Israel.
The Greens have put forward Waverley City Councillor Dominic Wy Kanak, while Angela Vithoulkas, one of Ms Phelps' colleagues on the Sydney City Council, is also running as an independent.
Polls open for early voting on Tuesday.