Three different challenges to vaccine mandates for particular workers are due to be heard urgently in the NSW Supreme Court on September 30.

Common between all three cases is a claim that parliament would not have intended to give Health Minister Brad Hazzard "the powers to breach bodily integrity" without clear legislative indication.

In a directions hearing on Friday, the minister's barrister Jeremy Kirk SC, sought to set aside a subpoena issued by lawyers for Natasha Henry and the five other claimants in her case.

Her lawyer Dr Jason Harkess referred to an interview with the Today Show in which Premier Gladys Berejiklian stated "firstly we weren't able to make the vaccines mandatory" and "it's not in our power".

"This is a significant admission," he said.

The subpoena sought any documents that the premier took into account prior to making her interview statement.

But Mr Kirk said the statement was "made in passing" 23 days ago by the premier who was not the decision maker.

Describing the move as "a stunt" and lacking any real forensic purpose, he also said any cabinet discussions would be subject to privilege.

In setting the subpoena aside, Justice Robert Beech-Jones said it was suggested that the premier made an admission there was no legal power to make the public health orders.

But he said she was not named as a party to the proceedings, nor was she the person conferred with the authority to make public health orders.

"Secondly, it must always be remembered that the question as to whether there is legitimate authority to make the impugned orders is a matter for the court," he said.

Any admission would be of little, if any, forensic value.

A second case involves Belinda Hocroft, a senior constable in NSW Police Force's mounted unit, who wants the court to invalidate a law preventing her from working outside her local council area before she has one dose.

Ms Henry's and a case brought by Al-Munir Kassam attack other elements of vaccine mandates.

They will also attempt to show the laws are for an improper purpose, breach privacy, breach natural justice and that the minister considered irrelevant matters when writing the laws.

Mr Hazzard is defending each case.

Australian Associated Press