West Australian Liberals will meet in Perth on November 7 to replace retired minister Mathias Cormann in the Senate.
The party meeting will also choose the WA Liberal Senate ticket for the next federal election, with minister Michaelia Cash widely expected to take the top spot.
However, it is expected her party room colleague Dean Smith could face a battle for second place on the ticket.
Senator Smith, the government whip in the Senate, is expected to face off against former WA state environment minister Albert Jacob, businessman Ben Small and the party’s policy committee chairman Sherry Sufi.
The first and second candidates on the ticket are virtually guaranteed to secure a Senate seat, while the third is possible, and the fourth and fifth placeholders extremely unlikely under the upper house voting system.
Media reports suggest Jacob’s conservative backers are gunning for Senator Smith over his support for same-sex marriage.
Cormann is Australia’s nominee for secretary-general of the OECD.
The WA Greens have already chosen their lead candidate for the Senate, former police officer Dorinda Cox, replacing retiring senator Rachel Siewert.
Labor is expected to wait until after the WA state election in March to pick their ticket.
Paul Osborne in Canberra