You will recall the frantic negotiations in the days leading up to Bernadette O'Neill's appearance at the Senate Estimates hearing of 15 February, 2012 where she announced the "independent" review into the FWA Thomson investigations.

Recall Val Gostencnik recommended KPMG and that recommendation was accepted and implemented.

Here's a report from AAP carried by the SMH a few days before.   Note the appearance of the word "interference" in this report.

This is the first time and only time I can find the word "interference" used prior to this.   Even in the AAP report the quotations from Mr Williams and Mr Jackson use words like "nobble the investigation" or "make sure the investigation was done properly".

I've always wondered why KPMG's terms of reference would specifically refer to "interference" throughout.

Watchdog warned of HSU probe interference

The industrial watchdog was so concerned about possible political interference in the Craig Thomson investigation that it got the Australian government solicitor involved, a union official has claimed.

Health Services Union general secretary Kathy Jackson has publicly released her response to an investigation into her union.

Fair Work Australia has spent almost four years probing whether Ms Jackson, former union president Michael Williamson and former union secretary Craig Thomson, now a Labor MP, breached civil or criminal law in their handling of union finances.

Mr Thomson has denied allegations he used union credit cards for prostitutes and cash withdrawals between 2002 and 2007.

All three have been asked to respond to the investigation's findings by March 5, before Fair Work Australia determines what further action to take, including a possible referral to criminal prosecutors.

The opposition has accused government ministers and officials of interfering in the investigation, given that losing Mr Thomson's NSW seat of Dobell could lead to the fall of the Gillard government.

Ms Jackson said she had warned former industrial registrar Doug Williams, the head of Fair Work Australia's predecessor body until his retirement in late 2010, of possible political interference in the inquiry.

In the documents, Ms Jackson quotes Mr Williams as saying in 2010: "I know that the allegations against Craig Thomson can bring down the government and that there are powerful people in the ALP who might make an attempt to nobble the investigation from the inside after I leave.

"I got the AGS (Australian Government Solicitor) involved in an attempt to make sure that doesn't happen and that the investigation is done properly."

Prime Minister Julia Gillard has denied any government interference in the inquiry, but previously has admitted her chief of staff Ben Hubbard, when she was workplace minister, had contacted the industrial watchdog in 2009 to check the accuracy of a media report.

Ms Jackson says in her rebuttal to the allegations against her that she had been "threatened and intimidated by persons in powerful positions" to give up her whistleblowing efforts.

Fair Work Australia has alleged Ms Jackson failed to attend four union national executive meetings and had failed to submit the union's 2007 accounts.

But Ms Jackson said she had acted properly at all times and had followed FWA's advice in dealing with the accounts, which covered the period during which Mr Thomson was secretary.

The issue is expected to be aired when parliament resumes for the year on Tuesday.