Sarah Hanson-Young's defamation lawsuit against a fellow senator will proceed with the Federal Court rejecting a bid to have it halted.
The Greens senator is suing Liberal Democrats Senator David Leyonhjelm over interviews he gave between June 28 and July 2 to Sky News, Melbourne radio station 3AW and the ABC's 7.30 program, and a media statement posted on Medium.com on June 28.
In the material, he elaborated on his comment to Senator Hanson-Young on the floor of parliament to "stop shagging men" amid a debate on legislation seeking to prevent violence against women.
In his application to have the case stayed, Senator Leyonhjelm argued that parliamentary privilege precluded him from running a truth defence.
Among other contentions, Senator Leyonhjelm said any reputation damage arose from Senator Hanson-Young's own words when she said "he's slut-shaming me" during a radio interview.
The court was told the Greens senator denied saying all men were rapists as attributed to her and Hansard did not record her saying those words.
In his judgment on Wednesday, Justice Richard White dismissed Senator Leyonhejlm's application although his counsel flagged a likely appeal.
The judge also ordered Senator Leyonhjelm pay Senator Hanson-Young's costs in relation to the application.
But the senator said the rulings would not affect his determination to win.
He described the action against him as "petty and pointless" and said it would "ultimately fail".
"Politicians should not be in the business of suing other politicians," he said.
In his reasons, Justice White said aspects of Senator Leyonhjelm's action "lacked merit".
He said the senator's claims that some parts of Senator Hanson-Young's case were frivolous or vexatious could not be sustained.
On the issue related to parliamentary privilege and Senator Leyonhejelm's ability to mount a defence, Justice White ruled such questions "may turn out to be hypothetical" depending on the determination of what Senator Hanson-Young did or did not say in parliament.
In her action, Senator Hanson-Young argues she was defamed by Senator Leyonhjelm's portrayal of her as a hypocrite and misandrist, in that he alleges she said words in parliament that were "tantamount" to claiming all men are rapists but "nevertheless had sexual relations with them".
"A person is not entitled to walk outside of parliament and fabricate an assertion as to what was said and attempt to defeat a defamation claim under the guise of parliamentary privilege," her barrister Sue Chrysanthou told the court previously.
The case will return to court on December 18.