Moira Deeming has lodged a legal action against Victorian Liberal Party state president Brian Loughnane, which is listed to be heard in the Victorian Supreme Court on Friday morning.
The latest round of Liberal infighting comes less than five months out from the November 28 state election, with party executives, including Mr Loughnane, planning to meet on Friday evening to determine Mrs Deeming's candidacy.
The upper house MP had made a police complaint against colleague Matthew Guy, alleging he assaulted her by grabbing her "violently" in a headlock at a gala dinner on May 23.
Victoria Police investigated the incident and found "there was no offence detected".
Mr Guy has demanded a public apology from Mrs Deeming.
"There was no ambiguity. I did not do what was alleged. The CCTV proves this. It did from the start, and Victoria Police agree," he said.
Mrs Deeming has since claimed she misunderstood the meaning of headlock, but has refused to apologise.
She has been invited to the state executive meeting to tell her side of the story, but whether she attends is yet to be seen.
Opposition Leader Jess Wilson on Thursday refused to answer questions about the process, but told reporters Mr Guy's reputation had been harmed and she had directly asked Mrs Deeming to apologise.
"I think he deserves an apology," she said.
"That is the right thing to do, and Moira has decided that's not the case. And now the state executive will meet."
Pauline Hanson has also declared she would not offer Mrs Deeming a position at One Nation.
Senator Hanson said Mrs Deeming's refusal to apologise to Mr Guy showed the first-term MP could not "admit that she got it wrong".
"You don't do that to your fellow colleagues," she told 3AW radio.
"I want a person with integrity and honesty, and I don't see that."
The scandal is yet another flare-up of what the public would see as disunity and disorganisation in the party, Monash University political scientist Zareh Ghazarian said.
"This is arguably the most critical point for the Liberal leadership right now to clear their internal problems," he told AAP.
"This has to be resolved as quickly as possible because it's already taken up a lot of political coverage ... it has hobbled the party significantly."
In a statement, Mrs Deeming's lawyer Tim Houweling said his client's complaint was made "honestly, in good faith and only as a matter of last resort".
He referred to CCTV footage that shows Mr Guy sitting at a table and talking with Mrs Deeming and another man.
The former leader appears to place his hand on Mrs Deeming's upper back or shoulder area and pull her in to say something before doing a similar gesture with the man.
The lawyer said Mr Guy had maintained a grip as Mrs Deeming attempted to pull away, and this physical contact was "unexpected, unwelcome, physically painful and caused her to feel fear and confusion".
Mrs Deeming successfully sued former leader John Pesutto for defamation when he implied she was associated with neo-Nazis after they gatecrashed a rally at parliament she attended.
