A stoush is brewing over the admissibility of expert evidence in Bruce Lehrmann's defamation trial, with the former political staffer set to object to a psychologist's views on the rarity of false rape complaints.
Mr Lehrmann's lawsuits against Network Ten, television personality Lisa Wilkinson and the Australian Broadcasting Corporation returned to the Federal Court on Monday, when Justice Michael Lee decided to hear the cases together.
It was also confirmed that Mr Lehrmann and Brittany Higgins, the former colleague who accused him of rape, would be among the witnesses to testify at trial.
Mr Lehrmann is suing Ten and Ms Wilkinson over a February 2021 story on The Project, which revealed Ms Higgins' claims of being raped at Parliament House two years earlier.
He is also pursuing the ABC for damages over its decision to run a live broadcast of Ms Higgins addressing the National Press Club in February 2022.
Tim Senior, junior counsel for Ten and the ABC, indicated on Monday that the commercial station would seek to rely on two expert reports.
The first, a 92-page document written by psychologist Christopher Lennings, delved into what Mr Senior described as "the responses and reactions of victims of sexual assault".
Mr Senior said the other proposed expert evidence was from a toxicologist, who would give their views about Ms Higgins' level of intoxication on the early morning of the alleged rape.
Matthew Richardson SC, representing Mr Lehrmann, told the court he was "highly unlikely" to take issue with the toxicologist's evidence.
But his position was different in relation to the report about the typical behaviours of sexual assault victims, which was said to "posit that false complaints are rare".
"There will certainly be an objection to that evidence," Mr Richardson told Justice Lee.
"It really appears to be an analysis of academic papers."
It was, ironically, academic papers about sexual assault that derailed Mr Lehrmann's criminal trial when a rogue juror defied warnings and conducted independent research.
Mr Lehrmann maintains, in the wake of a rape charge being discontinued, that he did not rape Ms Higgins in the office of their former boss, Liberal senator Linda Reynolds.
Ten and Ms Wilkinson will allege he in fact did as they defend his defamation action by arguing, among other things, that Ms Higgins' rape claims were true.
The ABC is also fighting the lawsuit levelled at it, and will rely in part on a new public interest defence.
It had previously been unclear whether the case involving the ABC would be heard at the same time as the proceedings against Ten and Ms Wilkinson, which were due to commence on November 20.
On Monday, Justice Lee decided to hold a joint trial and delayed its commencement until November 22.
The judge is set to consider the admissibility of Dr Lennings' report before the trial begins.
Mr Richardson indicated the evidence relevant to the ABC case was unlikely to take more than a day of the roughly four weeks set aside for the trial, with only five witnesses.
He said some of them may not even be required for cross-examination.
The proceedings involving Ten and Ms Wilkinson will involve a much greater number of witnesses, with Mr Senior saying the network was planning to call 28 people.
These included Ms Higgins.
Mr Lehrmann also sued the publisher of news.com.au and the website's political editor, Samantha Maiden, for defamation.
Those proceedings were to be heard alongside those involving Ten and Ms Wilkinson until the parties reached a settlement in May.
