The decision by Western Australia's opposition leader to stand down has prompted one of the state's two Liberal MPs in the lower house to challenge for the party leadership.
WA opposition leader Mia Davies announced her resignation on Friday, saying she didn't have enough "fuel left in the tank" to go on.
Her decision has prompted Liberals deputy leader Libby Mettam to challenge David Honey for the party leadership.
Mr Honey said he will fight to keep his job as the parliamentary leader of the WA Liberal Party, with a special partyroom meeting scheduled for Monday.
The Liberals were hammered at the 2021 state election, winning only two seats in WA's lower house to the Nationals' four.
Both parties formed an opposition alliance with Ms Davies as opposition leader.
Following Ms Davies' resignation, Ms Mettam contacted Dr Honey saying she was challenging him for the party leadership. She also contacted her seven upper house colleagues.
"I believe we have not been as effective as we should have been and change is required now to allow the Liberal Party to develop a strong, diverse, connected and competitive team," Ms Mettam wrote.
"It is my view that a leadership change is done as a matter of urgency, as we see an increasingly arrogant and self-serving government that takes West Australians for granted."
Mr Honey said it was Ms Mettam's right to stand for the leadership and it would be disrespectful to speculate about how the partyroom members would vote.
"I hold Libby in high regard," he said.
"Regardless of what happen's on Monday, Libby and I will continue to have a great working relationship."
Ms Davies is also stepping down as the leader of the WA Nationals, but will remain on the back bench until the 2025 election.
She told reporters on Friday night she had spent the summer thinking about her parliamentary career and what it would take to contest the March 2025 state election.
"I don't have any fuel left in the tank to go beyond that election."
The National Party's federal leader David Littleproud said Ms Davies had left a strong legacy and was a role model.
"Ms Davies broke glass ceilings and rose through the political ranks due to her hard work ethic, strong morals and tenacious attitude," he said.
Her resignation from the roles would be effective as of the next meeting of the parliamentary Nationals, which is likely to also be scheduled for Monday.
