West Australian Nationals MP Jacqui Boydell says she has experienced bullying, threats and intimidation within her own party.
The former deputy leader, who is retiring at the March state election, says she has been compelled to speak up following the airing of an ABC Four Corners investigation into the treatment of women by federal Liberal MPs in Canberra.
"I have remained silent on those issues in the interests of the party, and I have let myself down in the process," she told parliament late on Tuesday.
"But worse than that, I have let down the women who stand behind me in the lay organisation who have also suffered these issues.
"I have asked people in the organisation to assist me to deal with those issues, rather than make a public statement at the outset because if my interest was really to address the problem, I felt that I had an obligation to try to do that internally within the organisation.
"That has failed me."
Ms Boydell quoted former Liberal MP Julia Banks, who spoke of women being portrayed as "the bad ones, the liar, the troublemaker, the emotionally unstable or weak, or someone who should be silenced" when they called out bad behaviour.
"Unfortunately, that is the culmination of a mindset that cannot be addressed unless the unconscious bias of those individuals who run that sort of background intimidation is addressed," Ms Boydell said.
She added that she expected to face calls for her resignation from within her own party.
"I cannot leave this place with my integrity in place if I do not shine a light on this issue and stop being one of those women who walks past or does not address an issue I have experienced," she said.
In a brief response, senior Labor MP and Education Minister Sue Ellery applauded Ms Boydell for speaking up.
"I want to place on the record my admiration for you for speaking up tonight, because the culture of politics is that some will seek to make you pay even more of a price than you have already paid," she said.
Premier Mark McGowan earlier on Tuesday said he hadn't watched the Four Corners program but was not aware of any similar issues within WA's parliament.
The WA Nationals have been contacted for comment.