Prime Minister Julia Gillard says she never personally benefited from a union fund which she helped set up for free, and off the books, when she was a lawyer 17 years ago.
Ms Gillard held an hour-long news conference at Parliament House in Canberra on Thursday to deal with "false and highly defamatory" claims about her work with law firm Slater & Gordon in the 1990s.
It was the first time the prime minister had spoken in detail about the circumstances behind her resignation from the firm and her role in establishing the Australian Workers Union (AWU) Workplace Reform Association in 1995.
Ms Gillard said she had decided to address claims published on the internet and in the mainstream media, particularly after a report on Thursday wrongly implied she had engaged in fraudulent behaviour when doing the legal work to set up the association.
She said her understanding was the purpose of the association was to support electioneering by AWU officials and engage in fundraising activities.
Apart from doing the legal groundwork, she had nothing more to do with it.
"I had no involvement in the working of the association," she said.
"I provided advice in relation to its establishment and that was it."
Ms Gillard said she had no knowledge of allegations the association was being used for personal purposes by AWU official Bruce Wilson, her then partner, until controversy arose in the AWU in 1995.
She then broke off her relationship with Mr Wilson.
Police investigated Mr Wilson and the association, but no prosecution was ever launched.
Asked if any of the funds had been use to pay for renovations on a Melbourne home she owned at the time, Ms Gillard said: "I paid for the renovations on my home."
Ms Gillard resigned from Slater & Gordon in 1996 following an internal review of the AWU matter.
But there was also "growing tension and friction" among the partners as the firm was undergoing changes.
"It had long been an aspiration of mine to move to a political career," she said.
During the internal inquiry in 1995, Ms Gillard is reported to have said "every union has what it refers to as a re-election fund, slush fund, whatever, into which the leadership team puts money so that they can finance their next election campaign".
The prime minister conceded on Thursday it wasn't the best choice of words.
"Some of the discussions we are having (in the interview) are of a casual, even jovial, nature," she said.
"It wasn't the best form of words, but I'd ask people to assess the form of words in which it was being used."
Asked if she had acted ethically at all times, Ms Gillard said: "Yes."
The prime minister said she had not opened a file on the work for the association because at the time it was not unusual for the firm to do free legal work for union officials and unions.
Ms Gillard said she wanted to clear the air, but did not believe "misogynist nut-jobs" on the internet would ever give up their "malicious" campaign against her.
She compared their campaign to the false rumours circulated in the United States about President Barack Obama being a Muslim and not having been born in the USA.
She hoped that over time "highly professional, ethical journalism" would become more valued.