In a roundtable hosted by the classically liberal and free-market think-tank the Centre for Independent Studies in June 2013, Mr Heydon took aim at Labor's regulation of the charities sector. Under fire ... royal commissioner Dyson Heydon was due to be a guest speaker at a Liberal party fundraiser. Credit:Simon Bullard At the time the comments were made Mr Heydon was recently retired from the High Court, former Labor leader Julia Gillard was still prime minister and it was about eight months before Mr Heydon was appointed by the Coalition to head the Royal Commission into Trade Union Governance and Corruption. "Let me just ask what is the point of the Charities Bill 2013? Why seek to enact it just before an election at a time when the government is borrowing $1 billion a week just to pay the public service?" Mr Heydon said. "Is it an illustration of the fact that the tendency of the Rudd government to do non-substantive things like make speeches, and appoint committees and hold summits and so forth, survived even after Mr Rudd ceased to be prime minister?" Mr Heydon said.

"Or is it just really the production of some boffins in the Treasury or some other department?" he said. "Insubstantial": Former Labor prime ministers Julia Gillard Kevin Rudd. Credit:Getty Images Labor seized on the historical comments as further proof Mr Heydon is unfit to continue overseeing the royal commission. Labor frontbencher Tony Burke, who contributed to Mr Rudd's political assassination in 2010, asked Mr Abbott in question time if Mr Heydon's 2013 address was a job application for the royal commission job. Royal commissioner Dyson Heydon. Credit:Louise Kennerley

"The idea that this is somehow evidence of bias, that's evidence of gentle tolerance of the most incompetent government in history," Mr Abbott said to the house. Mr Abbott, who has previously described the Sir Garfield Barwick lecture as a fundraiser, attempted to say on Wednesday that it was a only a networking event. "Members opposite are trying to suggest that because Dyson Heydon AC QC agreed to go to a Liberal event, not a fundraiser, not a fundraiser, but a networking event, once he was no longer a royal commissioner, once he was no longer a royal commission, somehow he did the wrong thing?" he said. "That's it, is it?" Mr Heydon's comments emerged as News Corp reported Mr Heydon is being paid $1 million per year to head the royal commission.

The ACTU has confirmed it will apply for Mr Heydon's immediate disqualification. Mr Heydon is resisting calls to step aside and is due to rule on Friday whether he is impartial and fit to continue in the role. The royal commission has so far called federal Labor leader Bill Shorten as well as Ms Gillard as witnesses. Unions this week forced the royal commissioner to release all his correspondence relating to his now aborted speaking engagement. The emails showed Mr Heydon was told from the outset that the event was a Liberal party event. The opposition has moved a motion in Senate in an attempt to request the Governor-General to revoke the letters patent which establish the royal commission. In the event the motion is passed in the upper chamber, the Governor-General Sir Peter Cosgrove would be highly unlikely to agree to such a request. Follow us on Twitter