Greens leader suspended from parliament

Greens leader Richard Di Natale has refused to withdraw calling Nationals senator Barry O'Sullivan a pig during an ugly spat which saw him suspended from parliament.

A fiery exchange broke out in the upper house on Tuesday when Senator O'Sullivan said there was a "bit of Nick Xenophon in" the Greens' Sarah Hanson-Young.

The comment enraged Senator Di Natale, who took aim at Senator O'Sullivan with a barrage of insults.

"He's an absolute pig. He should be booted out. He's a disgrace," he shouted across the chamber.

"You grub."

Senator O'Sullivan insisted there was no double meaning to his comments, arguing he was referring to Senator Hanson-Young not turning up to an inquiry.

"We have endured on this side days of sexist filth coming from that man. He is a pig," a furious Senator Di Natale said.

Senate President Scott Ryan gave Senator Di Natale multiple opportunities to withdraw his remarks, but he refused and was booted from parliament for the rest of Tuesday.

The last use of the rule was in 2004, which involved former Greens leader Bob Brown.

An emotional Senator Hanson-Young said Senator O'Sullivan and conservative independents Fraser Anning, Cory Bernardi and David Leyonhjelm were "cowards" who had spent months levelling slurs at her.

"You are not fit to be in this chamber. You are not fit to call yourselves men," Senator Hanson-Young said.

She backed the Greens leader for calling out Senator O'Sullivan's "reprehensible" remarks.

"That is what real men do. Real men don't insult and threaten women," Senator Hanson-Young said.

"They don't slut shame them. They don't attack them and make them feel bullied in their workplace."

In June, Senator Leyonhjelm told Senator Hanson-Young to "stop shagging men" in parliament sparking a bitter row which led to an ongoing civil court case.

One Nation leader Pauline Hanson described Senator Hanson-Young as a "great actress" after saying she saw nothing sexist about Senator O'Sullivan's comments.

"Using this sexist tag because she's a female doesn't wash with me and a lot of other people," she said.

After almost two hours of insults, petty parliamentary tactics and chaos, Senator Ryan told senators to reflect on the period before they returned to work on Wednesday.