Influential Tasmanian conservative powerbroker Eric Abetz has been demoted to third place on the party's senate ticket in a shock preselection vote.
It could signal the end of Mr Abetz's almost three-decade senate career, given that third place on the ticket is difficult to win.
Mr Abetz lost votes to outer ministry senate colleague Jonno Duniam in first place, and senator Wendy Askew in second.
It was widely speculated that Mr Abetz and Mr Duniam would take the top two positions at the next federal election, with Ms Askew in third.
Tasmanian electoral analyst Kevin Bonham said Mr Abetz's senate seat was not unwinnable at the next poll, but he was in a risky position.
"Ever since he got into the senate he's been top of the ticket," Mr Bonham told AAP.
"There's never been any direct test of his popularity and now he has to actually fight for votes for the party as well as himself."
Considerations that could have swayed the 67 rank-and-file members who cast votes in the preselection, Mr Bonham said, were that Mr Abetz has long been a politically controversial figure, that he is close to retirement age and that it would not have looked good to demote a woman to third place.
Mr Duniam, 38, entered the senate in 2019. He is seen as an up-and-comer in the Liberal Party and is technically more senior than Mr Abetz because of the outer ministry position he currently holds as Assistant Minister for Forestry, Fisheries and Industry Development.
Mr Bonham said Mr Duniam was a conservative Liberal and had the appeal of youth and would not detract from the party's electoral appeal.
Wendy Askew was elected to the senate in 2016 and is chair of the senate's community affairs legislation committee.
