The Turnbull government has not decided if it will allow senators other than those on the crossbench – key to the success of its industrial relations reforms – to access secret volumes of the trade union royal commission's final report.
The Department of Prime Minister and Cabinet is arranging for crossbench senators to view confidential volumes of the report. It was previously understood that there was only one secret volume, which commissioner Dyson Heydon requested be kept confidential as it contained 29 threats to witnesses who could be physically harmed if their identities were revealed.
The move follows Senators Jacqui Lambie and Glenn Lazarus' pledge to continue opposing the government's signature industrial relations reforms until they could view this volume. Senator Lazarus has said this is needed to allow him to make a fully informed decision on the bills.
It is understood that the government will redact all information that could identify witnesses named in the volumes, and will not provide hard copies to senators.
A spokeswoman for Employment Minister Michaelia Cash conceded the government had not decided whether it would extend access to the volumes to other senators. She could not say why others should not similarly be able to view them.
Ms Cash said that the government would continue to engage with crossbench senators on all legislative priorities including those relating to the commission's findings.
Senators Lazarus, Lambie and Ricky Muir last year twice voted against government bills to reinstate a Howard-era building watchdog and to impose stricter penalties on union officials who breach their duties, with Labor and the Greens. The Senate twice rejected the latter bill, leaving open a potential trigger for a double-dissolution election.
The Coalition will try again this year to pass both reforms following the royal commission into trade union governance and corruption, with Prime Minister Malcolm Turnbull saying it would become an election issue if the Senate blocked new laws.
Without Labor and the Greens' support, it will need six of the eight cross-benchers to vote for the legislation.
Shadow employment spokesman Brendan O'Connor and shadow attorney-general Mark Dreyfus, QC, said on Sunday that all parties should be provided the volumes "if Malcolm Turnbull wants to rely on these secret volumes to make the case for his legislation".
They called the move a "cynical attempt to win support for their crackdown on workers' rights" in defiance of Commissioner Heydon's request that they be kept confidential.