Kathy Jackson was not the one who blew the whistle on Craig Thomson’s dodgy use of a union credit card, Australian journalist Brad Norington writes in a new book published this week on the former Human Services Union whistleblower, who was later found guilty of misappropriating union funds.

In one of several extracts from Norington’s book to appear in The Australian this weekend, the senior journalist writes that Jackson had “no role in leaking the damaging ­information that led to his conviction over misusing union credit cards on prostitutes”. Norrington writes:

“[She] claimed credit for leaking the Thomson information to then Fairfax journalist Mark Davis as early as 2009. When I asked her in late 2013 if she leaked the Thomson information to Davis, Jackson replied: ‘Of course I did it.’ Fellow author Aaron Patrick confirmed Jackson had told him the same thing during the writing of his 2013 book on Labor’s woes, Downfall.

“But Jackson did not leak the story that kicked off the HSU scandal on Thomson, whose vote in parliament became crucial to Julia Gillard’s one-seat Labor government majority after 2010. The real source confirmed that the motive for exposing Thomson was deep-seated frustration at the failure of HSU officials, including Jackson, to pursue Thomson.

“Confirmation that Jackson was not the leakier makes sense of some of her other behaviour. She did not personally move against Thomson until a unanimous HSU national executive vote to refer him to police in August 2011.”

The claim that she had leaked against Thomson, Norington claims, was useful to Jackson’s bid to gain control of the HSU.

In another extract, Norington writes of Jackson’s initial firm friendship then growing disagreements with Bill Shorten. At a party in 2001, a disagreement over a Labor preselection between the two devolved into an acrimonious food fight:

“She picked up a bowl of ice-cream and threw it at him. He threw something at her. It was starting to turn into a food fight. He grabbed her hand as she was about to throw something at him again. The ice-cream was so cold that it burnt her hand. Everything stopped, and then she went around for the rest of the night saying, ‘Look at what he’s done to me, a pregnant woman’.”