Unions report secret for a reason: Cash

The federal government is refusing to budge on requests to publicly release a redacted version of a secret volume of the trade union royal commission's final report.

Crossbench senator Glenn Lazarus wants the confidential volume made public but Employment Minister Michaelia Cash says it is confidential for "very good reasons".

"They will not be made public," she told reporters in Queanbeyan on Friday.

Crossbench senators will be allowed see the confidential volume to help them deliberate on draft laws cracking down on union corruption.

But Senator Cash says she's still deciding whether they'll see the redacted version or the full six volumes.

"The government is considering its position in relation to that," she said.