The defamation trial between the Daily Telegraph and Oscar-winning actor Geoffrey Rush would have to be delayed until next year if the newspaper is successful in its last-minute attempt to call a new witness.

On Friday, the federal court heard that the Telegraph wanted to call a new witness, who it said would help its defence against Rush.

The federal court judge Michael Wigney has imposed an interim ban on identifying the newspaper’s proposed new witness, who he dubbed “X” on Friday.

Rush is suing the Telegraph over a series of articles published at the end of November and the beginning of December in 2017, alleging he behaved inappropriately towards cast-member Eryn-Jean Norvill during a 2015 Sydney Theatre Company production of Shakespeare’s King Lear.

The trial has run for the past two weeks, but the Telegraph has sought to admit witness X’s evidence after they were contacted last Friday by Norvill’s solicitor, Arnold Bloch Leibler partner Leon Zwier, with information that “X” would be willing to give evidence.

Rush and Norvill were in court on Friday to hear the argument around whether witness X’s 85-page statement should be included.

The Telegraph’s barrister, Tom Blackburn SC, said the new witness would help the newspaper defend imputations that it alleged Rush was a “pervert, a sexual predator and of inappropriate behaviour of a sexual nature”.

Wigney reserved his judgment on the amended defence until Tuesday, but made his displeasure clear on Friday afternoon.

“Your client chose to publish,” he told Blackburn. “Maybe they should have made some more inquiries before they published.”

Wigney said the new witness would mean “essentially an entirely new set of allegations [and] an entirely new set of witnesses”.

“What about Mr Rush’s evidence? He was in the witness box for three days. He would have to wait six months for these new matters to be determined [and] would have to be recalled, among other things.

“From the very first case-management hearing, it was made abundantly clear that Mr Rush was anxious to have this case heard at the very earliest opportunity.”

He said he was concerned about the impact of the decision on Rush’s health and finances.

“That, to be blunt, is what concerns me,” Wigney said.

But while Blackburn conceded that the late application was “less than desirable”, he said the evidence of witness X “went to the heart of the case”.

He said Wigney faced a “stark evidentiary choice” in the case and that witness X would help the newspaper justify some of the imputations in Rush’s claim against it.

Rush has brought in a third barrister to seek to stop witness X’s evidence being heard.

Kieran Smark SC said the Telegraph was “quick to publish but slow to defend”.

He claimed the paper has “pestered” witness X “since shortly after the commencement of the proceedings”.

“When these publications were published [the] respondent hadn’t even secured the cooperation of Ms Norvill,” he said.

“They hadn’t spoken to her,” Wigney replied.