Liberal Senator Linda Reynolds and her former political staffer Brittany Higgins' high-profile defamation battle will go to trial in August.
The former defence minister, who plans to retire from politics at the next election, is suing Ms Higgins over a series of social media posts she says damaged her reputation.
Mediation has failed to resolve the case, which returned to the WA Supreme Court for a directions hearing on Wednesday.
A trial date of August 2 was agreed on, with the matter set down for about four weeks to accommodate more than 20 witnesses and parliamentary sitting dates.
Former prime minister Scott Morrison could be called as a witness, the senator's lawyer has previously said, along with other members of the federal Liberal Party, including Senators Michaelia Cash and Wendy Askew.
Although a trial date has been fixed, the parties could choose to attempt mediation again to resolve the case.
Justice Paul Tottle permitted Senator Reynolds to expand her claim to include a third incidence of defamation.
It's an allegedly defamatory tweet published by Ms Higgins' now-husband David Sharaz that Senator Reynolds' lawyer Martin Bennett has previously said the pair colluded on in January 2022, making her also a publisher and liable.
Some of the other matters expected to be heard at trial are a claim Ms Higgins was isolated and traumatised while campaigning for Senator Reynolds in Perth before the 2019 election, several months after she alleges she was raped by Bruce Lehrmann in Parliament House.
Mr Bennett said polling booth staff and Senator Reynold's family had provided evidence to the contrary about claims of a lack of support, along with photos of Ms Higgins at parties and her boss's birthday celebration about the same time.
"Senator Reynolds did provide support, every support to Ms Higgins," he said as he made submissions on some of the particulars and evidence in the case.
Senator Reynolds last week said she was determined to get justice over the alleged defamation and Ms Higgins' claims had "taken a huge toll on my mental and my physical health".
She said it was essential all parties accepted the findings of Federal Court Justice Michael Lee regarding Lehrmann "so that the many people who have been damaged by this whole saga can get justice and to get peace".
She said it was possible a settlement could still be reached and called for Ms Higgins to admit she was wrong and apologise.
Justice Lee in April delivered his judgment in Lehrmann's defamation case against Network Ten and journalist Lisa Wilkinson.
He found on the balance of probabilities Lehrmann did rape Ms Higgins, but the allegation of a political cover-up "was objectively short on facts but long on speculation".
Lehrmann is appealing against the Federal Court judgment.
Senator Reynolds was also pursuing Mr Sharaz, for defamation but he announced in April he would no longer fight the case and consented to judgment.
The former minister claimed he had also defamed her in a series of social media posts.
Mr Sharaz was ordered to delete three tweets, a Facebook post and an Instagram story from 2022 and 2023.
The damages Mr Sharaz will have to pay following his admission will be decided after Ms Higgins' defamation trial.
Lehrmann denies the sexual assault allegation. His criminal trial was aborted because of juror misconduct and Ms Higgins' mental health was cited as the reason for no retrial.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
