Outgoing Greens senator Lee Rhiannon has warned her party must resist careerism, leaking and bullying to guarantee its future.

Senator Rhiannon is leaving federal parliament at the end of the August sittings after losing her spot on the party's upper house NSW ticket in favour of Mehreen Faruqi.

The 67-year-old has in recent years been at the centre of factional brawling within the minor party, highlighted by a public bust-up with Greens leader Richard Di Natale.

Senator Rhiannon said the party could have a long and fruitful future, but urged it to remain progressive and democratic.

"That means resisting careerism, hierarchical control, bullying behaviour and the associated leaking and backgrounding," Senator Rhiannon told parliament on Monday.

She said a failure to reject that behaviour would reduce the Greens' contribution to social movements.

"We will lose members and individual members will be hurt," Senator Rhiannon said.

Senator Rhiannon was demoted on the Senate ticket months after being temporarily suspended from the Greens party room in 2017.

The bitter fight exposed long-running divisions between Senator Rhiannon's left faction and the party's centrists, including Senator Di Natale.

Senator Rhiannon, who defended her communist roots in her 2011 maiden speech, also took aim in her farewell speech at "McCarthyist" tactics of right-wing politicians and the media.

She called out "intense abuse" levelled at her during her stint in federal politics, saying her family had also been the subject of slurs during more than a decade in NSW parliament.