Prime Minister Julia Gillard used the Parliament's last sitting day of the year on Thursday to demand Opposition Leader Tony Abbott put up or shut up over accusations she had broken the law through her involvement in the 1990s AWU scandal.
Mr Abbott appeared on national television early in the day to claim Ms Gillard had broken West Australian law by helping her then boyfriend Bruce Wilson and his fellow union official Ralph Blewitt to establish an association linked to the Australian Workers Union.
The association's slush fund was subsequently allegedly defrauded by the two men. Ms Gillard has been under attack all week over her involvement, but she insists she is guilty of no wrongdoing and had only supplied legal advice as a solicitor working for the firm Slater & Gordon.
Mr Abbott's television interview was in response to Fairfax reports that Ms Gillard had written to the WA Corporate Affairs Commission in 1992 to deny the association was a trade union organisation, and in so doing enabled it to be incorporated.
The Prime Minister wrote to Fairfax chief executive Greg Hywood on Thursday morning claiming the media reports were misleading.
But in a surprise move later in the day, an angry Ms Gillard opened question time by calling for a suspension of standing orders to allow Mr Abbott 15 minutes to either substantiate his claims or unreservedly apologise to her.
Although the Opposition Leader was caught on the hop, he was not in an apologising mood. He used his 15 minutes to call for a judicial inquiry into Ms Gillard's conduct.
Mr Abbott described her as a lawyer who was ''dodgy and unethical'' and a Prime Minister who could not be trusted.
''Plainly there has been illegal and unethical conduct here,'' he said. ''Much of it has been facilitated at the very least by the Prime Minister and the advice she has given.''
But Mr Abbott did not directly repeat his accusation that Ms Gillard had committed a crime.
The Prime Minister then returned fire, describing Mr Abbott's speech as halting and nervous because he had no evidence to support his earlier claims. ''He had an opportunity today to put up and he has not been able to do so,'' she said.
''A decent man would apologise. A decent man would recognise that he has gone too far, that he has made an error, that he has relied on a false report.
''If the Leader of the Opposition was a decent man he would have used his 15 minutes to say he was wrong.''
Ms Gillard accused Mr Abbott of ''overreaching'' and said the opposition's sustained attack against her was ''ridiculous''.
Question time resumed with more AWU questions, led by Mr Abbott who had sat quietly for most of the week while his deputy Julie Bishop prosecuted the opposition's case.
But the Prime Minister had pre-empted Mr Abbott's attempt as chief inquisitor with her clever strategy to have him defend his earlier remarks.
The Parliament subsequently rose at the end of a combative week and a tumultuous year.
Most MPs have now left Canberra for the long Christmas break and will return in February prepared for an election year.