Julia Banks quit the Liberal Party after the leadership coup against Malcolm Turnbull in late 2018, sitting as an independent until an election the following year.

Ms Banks has blamed the prime minister's behaviour - describing it as "menacing" and "controlling" - for her decision to quit the party and leave politics.

The former corporate lawyer said Mr Morrison tried to portray her as a "weak petal" who had not coped with the mental strain of the leadership spill.

When the prime minister gave a press conference and took questions about Ms Banks' decision not to recontest the next election, he responded by expressing concern for her welfare.

"He wanted me silenced, he wanted me to be quiet, he wanted me out of the parliament; I mean, he wanted me out of the country," she told the ABC TV on Monday night.

"At that time, I thought, I'm challenging him and that was his response. His response was to drag me through this sort of sexist spectrum.

"A narrative that I was this weak, over-emotional woman, to the bully bitch. That narrative was played all the way through that three months."

Ms Banks says she was also told the prime minister's office was "backgrounding" against her, giving off-the-record briefings to journalists.

She had originally planned to serve out her term on the backbench under Mr Morrison's leadership but instead opted to become an independent, saying she rejected an offer to be posted to New York as a United Nations delegate.

"I had planned to go quietly," she said.

"But because of these attempts to silence me, either by sending me overseas or to convey this narrative about me, I thought 'I'm not going to limp out of this parliament'."

A spokesman for the prime minister said Mr Morrison was disappointed Ms Banks quit the party and had several conversations with her to understand what she was going through and what support was available.

"That included support for personal leave so she could take the time to recover from the upset many people suffered during that period," the spokesman told AAP.

"The prime minister absolutely rejects claims about the nature of those conversations."

When she first entered parliament in 2016, Ms Banks said it was like travelling back in time to the 1980s.

Ms Banks alleged she was subjected to an unwanted sexual advance at work by a coalition government cabinet minister when Malcolm Turnbull was prime minister.

A spokesman for Mr Morrison said he was not aware of the allegation but suggested any such behaviour was "completely inappropriate".

Ms Banks said parliamentary workplace culture had not improved under Mr Morrison's leadership, comparing his alleged treatment of her to former Liberal staffer Brittany Higgins and ex-Australia Post boss Christine Holgate.

"When you think about all the things Morrison has said about women who have challenged him in some way or form, he will use his power in that way," she said.

"We've got to stop putting this burden on women.

"We've seen a lot of names come out and Morrison's response to it has not been what (it would be) in other workplaces, where you have to make the tough calls against the perpetrators."

Labor frontbencher Katy Gallagher said allegations of backgrounding and condescending language indicated a pattern of behaviour.

"I have no reason to disbelieve what Julia Banks has outlined," Senator Gallagher told ABC radio.

"It's a pretty distressing story, I'd have to say, and it's no wonder she left."

Australian Associated Press