Ms Higgins' lawyer Rachael Young told the West Australian Supreme Court on Monday that her client, who is now pregnant, would not travel to Perth from her home in France to give evidence.

"The defence will not be calling Ms Higgins," she told the court. 

Ms Young said there were three reasons behind the decision.

"The first is the defendant is not obliged to go into oral evidence," she said.

"The second is ... we don't think we need to call Ms Higgins to satisfy Your Honour as to being successful in these proceedings. 

"The third is a matter of Ms Higgins' medical state."

Ms Young said Ms Higgins' condition would be detailed in confidential medical reports to be filed with the court.

Outside court, Senator Reynolds' lawyer Martin Bennett said she wanted the truth to come out after being denied an opportunity to test Ms Higgins during her compensation claim.

"I'm sure what Senator Reynolds would be unhappy about is the contest will not be her word against Ms Higgins. It'll always be a question of whether Ms Higgins says 'if I was well enough I could have come and answered these allegations'," he said.

"That's unsatisfactory. Linda Reynolds has waited years to vindicate her reputation and this is the day but these things happen in trials." 

Earlier on Monday, WA Liberal Party selection committee chair Jeremy Buxton gave evidence that the furore around Ms Higgins and her boss at the time would likely to have affected the senator's election chances if she had not chosen to retire at the next election.

While he said she had had been a well-regarded senator, Mr Buxton said Senator Reynolds could have "been struggling ... to get the third position" on the Liberal election ticket.

"it is very likely ... there would be a feeling among a considerable number of delegates that (she) had mishandled the situation in her office, that she may have been unethical in her cover-up," he said.

"She may well have been judged a little more harshly as a female senator that she did not adequately support a young female staff member, even if not all the allegations would be believed across the mass of the delegates, there would be a very considerable reservation putting her at a disadvantage to other colleagues who didn't have to answer those sorts of questions."

Mr Buxton said position three on the ticket was problematic and position four put a candidate in an unwinnable position unless there was a landslide.

He said Justice Michael Lee's Federal Court judgment in Lehrmann's failed defamation matter against Network Ten and Lisa Wilkinson, debunking allegations of a cover-up by the Morrison government, would have been helpful. 

But Mr Buxton was not sure it would have "covered all doubts, problems and insinuations on the matter".

The court also heard from Dr Antonio Di Dio who was called to parliament after the senator broke down in February 2021 in the days after Ms Higgins appeared on Network Ten's The Project.

He said he had been called because she had been experiencing chest pain.

Dr Di Dio described the senator as being "very anxious and very stressed" at the time.

"I had been asked to see her because of acute anxiety and this was confirmed during my meeting," he said.

Senator Reynolds was referred to a cardiologist and later to a psychologist and a psychiatrist. 

"I was concerned about the high level of anxiety and the profound effect that that was having on Senator Reynolds' work at the time," Dr Di Dio said.

"She was obviously was doing important work and was incapable of attending which was causing her emotional distress."

Lehrmann denies raping Ms Higgins and his criminal trial was derailed by juror misconduct.

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