A judge has ruled The Daily Telegraph cannot add a new defence witness in Oscar-winner Geoffrey Rush’s defamation case.

The newspaper last week applied to make the changes, but Federal Court Justice Michael Wigney said the amended defence proposed raised new allegations about Mr Rush’s conduct.

The judge said to amend the defence case so late in the trial would mean that a new trial would have to be conducted in 2019, which would be unfair on Mr Rush, who has already been in the witness box for three days.

Justice Wigney said Mr Rush’s case has been “consistent'” since it was filed and the actor has made no attempt to amend it.

The judge said the Telegraph has tried to “frustrate and impede” Mr Rush’s case at every stage of the proceedings, and the newspaper’s case is a “moveable feast”.

Justice Wigney acknowledged that the proposed amendments are of importance to the paper and reporter Jonathan Moran’s defence – but stressed the lateness of the application.

“The application to amend has unquestionably been made at an extremely late part of the trial,” he said.

“Mr Rush has already given evidence and been cross-examined over three days.

“There is also the potential other witnesses will have to be recalled.”

The judge said Mr Rush was a public figure and the court proceedings had already received extensive publicity.

He said public confidence in the judicial system would be undermined by unnecessary adjournments and delays.

Justice Wigney told the court: “In all the circumstances … the amendment should not be permitted and the trial should proceed.”

He ruled that an interim non-publication order on the proposed new evidence and the new witness – “witness X” – should remain in place.

The defamation hearing continues tomorrow with closing missions by lawyers for the Telegraph.

It is expected to finished by Thursday.

Mr Rush, 67, is suing over stories published in 2017 that he alleges portrayed him as a pervert and sexual predator during a Sydney Theatre Company production of King Lear.

The stories accused him of harassing a younger female cast member later revealed to be Eryn Jean Norvill, 34, who played Cordelia in the production in which Mr Rush had the lead role.

-ABC