Federal Minister Michaelia Cash will give evidence in the Federal Court case brought against the Registered Organisations Commission and others by the Australian Workers' Union (AWU), after her office tipped off the media to an Australian Federal Police (AFP) raid of AWU offices in late 2017.

Key points: Senator Cash fought the order to give evidence but her lawyer said she has since decided to appear

Senator Cash fought the order to give evidence but her lawyer said she has since decided to appear The case was launched by the AWU after Senator Cash's office leaked details about the raids to the press

The case was launched by the AWU after Senator Cash's office leaked details about the raids to the press Senator Cash's former staffer, who phoned media outlets about the raid, will also appear in court

Senator Cash had challenged the subpoena to appear but today her lawyer, Ben Jellis, told a pre-trial hearing in Melbourne "she's prepared to give evidence at a suitable time to accommodate parliamentary and ministerial commitments".

A trial is set down for five days in Melbourne beginning on February 11.

But the court heard it might run longer as Senator Cash will not be available most of that week because of Cabinet obligations and parliamentary sitting days.

On October 24, 2017 the AFP conducted raids on AWU offices in Melbourne and Sydney as part of an investigation into donations made to GetUp and Labor candidates when Opposition Leader Bill Shorten was head of the union.

It was later revealed Senator Cash's media adviser, David De Garis, had called media outlets tipping them off about the raids.

He resigned from her office and has also been subpoenaed to appear as a witness in a case the AWU has brought against the Registered Organisations Commission, and the Australian Federal Police.

Senator Cash has vehemently argued no wrongdoing in the matter, telling both the Senate and Senate Estimates she was not aware of her staffer's actions.

AFP officers at the Victorian Branch of the AWU in October, 2017. ( AAP: Julian Smith )

Mr De Garis lives in Perth now and works as a media adviser to the Australian Hotels Association.

His lawyer tried to get the court to agree to allow Mr De Garis to give evidence via videolink from Perth, rather than appear in person in court.

Mr De Garis argued it was inconvenient as he had to assist with a Senate Estimates appearance by the AHA at the time the trial was held and would be needed at short notice in his new job.

Herman Borenstein, QC, for the AWU argued Mr De Garis's testimony was too important for it to be possibly disrupted by poor video connections.

"He was the senior media adviser to the minister who said that he leaked details of the execution of the warrant to the media," Mr Borenstein said.

Justice Mordecai Bromberg rejected the application, directing Mr De Garis to appear in person.

He also granted a request from Senator Cash's lawyer to have access to the opening arguments that will be put forward by the AWU.

He turned down a request by the AWU to have the court suppress witness testimony when the court case begins.

