Victorian Opposition Leader John Pesutto has made a formal complaint after being served legal papers on the grounds of parliament.
Angie Jones, an organiser of the Let Women Speak rally in Melbourne, lodged defamation action against Mr Pesutto in the Federal Court on Tuesday.
The 2023 rally, headlined by Kellie-Jay Keen and attended by then Liberal MP Moira Deeming, was gatecrashed by a group of masked men who performed Nazi salutes.
All three women are suing Mr Pesutto, who has said he will vigorously contest the defamation proceedings.
On Wednesday, a woman approached the Victorian Liberal leader in the parliamentary precinct to serve Ms Jones' legal documents.
"They've already been served. My lawyers have them," Mr Pesutto said in a video of the interaction.
"I'm not required to take them - I'm a lawyer. This is outrageous."
Under parliamentary privilege, opposition business manager James Newbury said Mr Pesutto believed the woman confronted him in a bid to have the serving of the allegedly unsealed documents captured by the media.
"It was therefore a stunt as part of the ongoing and highly publicised legal actions of Ms Jones, Ms Kellie-Jay Keen and Ms Deeming of the other place," Mr Newbury told the lower house on Thursday.
"The member for Hawthorn is concerned that the events of Wednesday constitute a contempt of parliament and raise serious concerns about security for all members of parliament, staff and visitors who work and attend the parliamentary precinct."
Mr Pesutto's office has made an official complaint, with the matter referred to parliament's privileges committee for investigation.
In a letter sent to Mr Pesutto's law firm, Ms Jones' lawyer Katherine Deves said Mr Pesutto had "no explicit immunity" against service.
She said the woman was a friend of Ms Jones and described her as an elderly lady of diminutive stature who was polite and softly spoken at all times.
"The act of service did not in any way obstruct or impede either the house of parliament in the performance of its functions or obstruct or impede the member of Hawthorne (sic)," Ms Deves wrote.
"The act of service was not, therefore, an act of contempt."
Ms Jones' statement of claim, obtained by AAP, accuses Mr Pesutto of instigating a persistent public campaign against her.
The document alleges he caused serious harm to her reputation in a interview with Melbourne radio station 3AW and 15-page dossier distributed by his office.
It claimed the interview carried a series of defamatory imputations such as that Ms Jones is associated with "far right-wing extremist individuals and groups including Neo-Nazi activists".
"The degree of harm to Jones' reputation was self-evidently caused by the extent of publication and republication of such serious imputations to the world at large," the document reads.
"Pesutto published the same or similar imputations to those carried by the 3AW Interview repeatedly in his campaign against Jones."
Ms Jones is seeking aggravated damages.