New South Wales Greens MP Jenny Leong has used parliamentary privilege to deliver an explosive speech calling on her colleague Jeremy Buckingham to resign over sexual harassment allegations.

Key points: Jeremy Buckingham has rejected the call to resign

Jeremy Buckingham has rejected the call to resign Earlier this year a former Greens staffer also made allegations of sexual harassment against the MP

Earlier this year a former Greens staffer also made allegations of sexual harassment against the MP Jenny Leong said she could no longer stand by while "badly behaved men" were protected

Ms Leong said she had been elected to "speak up and speak out" and she "cannot stay silent anymore" about Mr Buckingham's behaviour.

She also accused him of behaving in an "intimidating manner" towards her.

She said she believed former Greens staffer Ella Buckland, who came forward to the ABC's 7.30 program earlier this year alleging Mr Buckingham touched her inappropriately in 2011.

"To Ella Buckland, who has shown strength by speaking out publicly about Jeremy's act of sexual violence towards her and the subsequent disgusting behaviour she has endured, let me say on the record that I believe you," she said.

Former Greens employee Ella Buckland made a complaint against Greens MLC Jeremy Buckingham. ( ABC News: Dave Maguire )

Ms Leong also indicated there were other party members who had concerns about what she described as Mr Buckingham's "unacceptable behaviour".

"Jeremy's actions and behaviour, some widely reported and documented and some still held in confidence which must be respected, have had a real and lasting consequence on individual women, members and former members of our party," she said.

"Beyond what has been articulated by Ella Buckland about how Jeremy behaved towards her I know there have been active volunteers who have stepped aside or resigned as members as a result of Jeremy's behaviour."

Ms Leong said she used to consider Mr Buckingham a friend, but she wanted to share some information about him that she thought "goes to character".

"On two occasions earlier this year Jeremy behaved in an aggressive and intimidating manner towards me, once in a public place and once in the corridors of this place.

"For a male Greens MP to behave in an aggressive manner, an intimidating manner towards a female Greens MP in the heart of her own electorate while people are passing by is clearly a sign of someone not being able to control their behaviour."

Federal Greens leader Richard Di Natale said the issues raised in NSW Parliament were serious and were ultimately a matter for the state party.

"I believe the most appropriate course of action is for Jeremy Buckingham to stand aside as a candidate for the next election," he said in a statement.

"I have communicated that to Jeremy today on behalf of the federal partyroom."

A spokesman for Mr Buckingham said he would not be standing aside.

'It is a societal problem'

Ms Leong said the party had failed to deal with the issues properly and she and Greens senator Mehreen Faruqi were both joining forces to call for Mr Buckingham to go, or be expelled by the party.

"Jeremy, you have had countless opportunities to take responsibility for this, to apologise to those impacted and to seek to address them, instead you have followed with further aggressive tactics.

"I know you feel like you are the victim of internal party attacks but you must acknowledge your role in this and stand aside before more damage can be done."

Ms Leong went on to say the problem was not specific to any party, nor limited to parliament.

"It is a societal problem," Ms Leong said.

"I am no longer going to be a part of a system that runs a protection racket for badly behaved men in this place or in society — it has to stop."

Jeremy Buckingham is the convenor of the Country Greens network. ( AAP: Tracey Nearmy )

Mr Buckingham issued a short statement after Ms Leong's speech indicating he would not be resigning.

"I reject Jenny Leong's characterisation of a couple of conversations we've had," he said.

He said the allegations relating to Ms Buckland had been investigated by an independent workplace investigation specialist and there had been no findings of wrongdoing.

Greens MP Cate Faehrmann said the party's sexual harassment policy stated if there was no adverse finding after a complaint, then it should not act in a prejudicial way against the person.

"Unfortunately a determined group of people in the party have relentlessly pursued Jeremy in a bid to force him to resign despite the investigation's findings," she said in a statement.

"As a woman, I am angry at the way this complaint has been used as a political weapon.

"This risks making it harder for all women who have experienced sexual harassment and assault to feel safe and supported to come forward."

Earlier this year Mr Buckingham was ousted from what is widely considered the last winnable spot on the Greens ticket by factional enemy David Shoebridge, so is unlikely to be re-elected in March.