The WA Greens Party is in disarray today after an acrimonious public falling out between two of its most prominent politicians.

The member for Fremantle Adele Carles has quit the party saying criticism from the party's leader Giz Watson had been a significant factor in her decision.

On Friday afternoon Mr Carles launched an attack on Ms Watson accusing her of knifing her and forcing her to go public on her affair with former Treasurer Troy Buswell.

Ms Carles emailed the Greens saying she had resigned from the party and would sit in parliament as an independent.

She says Ms Watson had threatened to release details of the affair to the media if Ms Carles didn't come clean.

Ms Carles says Ms Watson forced her to expose her private life.

At a news conference in Perth on Friday afternoon Ms Carles was asked directly if the party had knifed her.

"I would say Giz Watson did by not admitting about the bungle she made about that Friday media conference that she was going to do," she said.

Ms Watson rejects any suggestion she blackmailed Ms Carles into revealing her affair with Mr Buswell.

Ms Watson also denies she threatened the member for Fremantle.

"All those conversations were had with all our colleagues in the room and we have a very firm commitment, we had a very firm commitment to work with Adele, to do it together," she said.

Last week, Ms Carles admitted to a four-month affair with former state treasurer Troy Buswell.

Ms Carles says because of pressure and bullying from the Greens, her private life has been exposed and she says Ms Watson has still continued to criticise her.

"You know, I would have thought that would have been enough punishment, that I'm out there completely exposed, my whole public life is exposed here.

"That's still not enough for Giz Watson. She's still been on the airwaves bagging me in public. I can't understand that, I really don't understand that. And I can't work in a team where I don't have the support of the leader."

She says Ms Watson threatened to take the story of her affair with Troy Buswell to the media and that forced her to admit to it publicly.

"If anyone is going to say this I have to say this in my own words so that I can say it to the people of Fremantle that represented me, not Giz Watson as some school mistress telling the public about something naughty that I'd done."

But, Ms Watson says the story was going to be revealed anyway and she was attempting to help Ms Carles gain a measure of control.

"The combined thinking of the parliamentarians was if this story is going to be run, it would be better that Adele actually be given the opportunity to put it in her words."

The co-convenors of the WA Greens, Dee O'Neill and Scott Ryan, say they are disappointed with Ms Carles' decision but the party will respect it.

Mr Ryan said the deterioration of working relationships with Greens MP Giz Watson was behind the reason for her decision.

"She sees the relationship, particularly with Giz, having broken down and she doesn't feel like she can function within the parliamentary team without Giz's full support," he said.

Ms Carles was the only Greens member in the Lower House but will now remain as an Independent.