Public sector unions have called in their lawyers as they prepare to fight demands that they appear before the inquiry into leaks of confidential Foreign Affairs and Trade information.

They have also advised members not to appear before the inquiry unless they have a representative present.

In a circular to members, the Foreign Service Association said the scope of the inquiry was wide and that was also being questioned by the unions.

It had engaged Charles McGuinness, of Cullen Law, to provide guidance to the FSA and to any members "invited to assist the Rebstock inquiry".

Until it had clarified issues around the inquiry it advised members not to agree to meet the Paula Rebstock-led inquiry "nor provide information (such as questionnaires for staff overseas), without representation".

PSA secretary Brenda Pilott confirmed yesterday the unions had been asked to appear before the inquiry, which is operating under powers delegated from the State Services Commission.

The two unions were moving to establish their legal position "given that we are an independent organisation which is not part of the state sector, and the investigation is being carried out under the delegated powers of the State Sector Act".

The PSA would advise Ms Rebstock of its position in due course.

But a spokeswoman for the State Service Commission said the probe was under the Commission of Inquiry Act. That gave it power to summon any person "to give evidence, and to produce any papers, documents, records, or things in that person's possession or under that person's control that are relevant to the subject of the inquiry".

Witnesses have the same privileges and immunities as in a court of law.

The inquiry's terms of reference originally covered the leak of up to three Cabinet papers, which came after a string of embarrassing leaks as the ministry worked on plans to cut jobs.

Opposition from ministry staff forced the Government to water down the planned cuts. But the inquiry's scope was later extended to cover "all the relevant background facts surrounding the development of the Mfat change programme".

That included "the environment within which Mfat was operating during this period" and "who may have been responsible for earlier unauthorised disclosures during the development of the Mfat change programme".

In a May 23 letter to Ms Rebstock, released to The Dominion Post under the Official Information Act, State Services Commissioner Iain Rennie said he had always intended the inquiry to encompass a broad investigation. He was making the change to the terms of reference to avoid doubt.

"These aspects go to the heart of understanding what occurred and sets the context against which the standards of conduct required of state servants are to be considered."

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