Jobs Minister Michaelia Cash is holding out against calls for her to quit after police investigations into Australian Workers Union raids were referred to the commonwealth prosecutor.
The Australia Federal Police are under understood to have confirmed to the union it will have material with the Commonwealth Director of Public Prosecutions in the next two weeks.
AFP officers raided the union's Sydney and Melbourne headquarters last October as part of an investigation by the Registered Organisations Commission.
The raids drew scrutiny because journalists arrived at the offices before police after a tip-off from Senator Cash's office.
One of her advisers resigned after admitting to tipping off the media.
AWU national secretary Daniel Walton said the referral was troubling but not surprising.
But a spokesman for Senator Cash said it was an attempt by the AWU to distract from the issue of whether Labor leader Bill Shorten as union leader "secretly donated member money to his own organisation and own election campaign".
Australian Council of Trade Unions secretary Sally McManus said Senator Cash was driven by a hatred of unions.
"Michaelia Cash should have resigned long ago," Ms McManus told reporters in Melbourne.
But Liberal MP Luke Howarth hit back at the ACTU, saying they were "disgracefully" spreading rumours about coalition politicians.
"Most voters would not even have a clue about what's going on in relation to that issue," he told Sky News.
