NSW Nationals leader Paul Toole is expected to face a challenge from former agriculture minister Dugald Saunders when party MPs meet this week.
Mr Saunders, a former radio presenter and sports broadcaster who called the Sydney Olympics, has been the MP for Dubbo since 2019 when he succeeded former police minister Troy Grant.
Re-elected with a small swing towards him in last month's election, Mr Saunders had indicated an interest in the top job, Coffs Harbour MP Gurmesh Singh told AAP.
Mr Saunders declined to comment on the speculation on Tuesday.
All positions, including Mr Singh's position as party whip and Bronnie Taylor's deputy leadership, are made vacant after a state election and go to a vote at the first partyroom meeting, to be held on Wednesday morning.
Mr Toole, who has led the NSW Nationals since John Barilaro quit parliament in October 2021, was unavailable for comment but is expected to recontest the leadership.
He served as police minister and deputy premier in Dominic Perrottet's ministry.
At the March election, several MPs including Mr Toole and outgoing emergency services minister Steph Cooke enjoyed substantial swings towards them.
The loss of Monaro MP Nichole Overall, who was the only sitting National to lose her seat, has cut the proportion of women in the party room to 25 per cent which is below that of the Liberals, Labor and Greens.