Mr Heydon was listed as the keynote speaker at the Sir Garfield Barwick Address on August 26 at the Castlereagh Boutique Hotel in Sydney. Royal commissioner Dyson Heydon during hearings. Credit:David Geraghty An invitation written on a Liberal Party letterhead obtained by Fairfax Media says the $80 cost should be made to the Liberal Party of Australia's NSW division. It also calls for donations if people are unable to attend. "All proceeds from this event will be applied to state election campaigning," the invitation's fine print notes. A spokesman for Mr Heydon released a statement shortly before 11.30am saying he would now not deliver the address.

"As early as 9.23am this morning (and prior to any media enquiry being received) he advised the organisers that 'if there was any possibility that the event could be described as a Liberal Party event he will be unable to give the address, at least whilst he is in the position of royal commissioner'." Leader of the House Christopher Pyne shuts down an attempt by Labor to have Justice Heydon removed as royal commissioner. Credit:Andrew Meares Fairfax Media first contacted the commissioner's office at 9.35am on Thursday. Mr Heydon has excused himself from hearings three times today. Eric Abetz was an ardent supporter of Tony Abbott. Credit:Andrew Meares

Labor MPs rushed to the House of Representatives in a bid to have Mr Heydon removed from his role following the revelations. "This is conflicted, he is biased, the royal commission is a farce," Labor frontbencher Tony Burke told Parliament. Mr Burke attempted to suspend standing orders to move a motion urging the commissioner to disqualify himself. But the motion was unsuccessful because the government commands a majority. Speaking at a media conference shortly after, shadow attorney-general Mark Dreyfus called on Mr Heydon to release all communications between himself and the Liberal Party.

Greens MP Adam Bandt also said the royal commission must be terminated. "Any pretence of independence of the trade union royal commission is now gone," he said. And the royal commission must be immediately terminated." Attorney-General George Brandis addressed the same fundraiser in June 2010. A bio accompanying a photograph of Mr Heydon does not disclose he is currently serving as royal commissioner. In response to the invitation, Opposition Leader Bill Shorten said: "If it is true that a royal commissioner investigating Tony Abbott's political opponents is now attending a Liberal Party fundraiser, that is incredibly serious, incredibly concerning."

Prime Minister Tony Abbott vowed to establish the royal commission in the wake of the Australian Workers Union slush fund scandal, which dogged former prime minister Julia Gillard. It was also established to examine the corruption uncovered at the Health Services Union involving the former Labor MP Craig Thomson. Mr Abbott refused to comment on the scandal when asked about it at a media event in Canberra on Thursday. In selecting Mr Heydon to head up the royal commission, Mr Abbott said in July: "There is no more distinguished person in the legal profession than Justice Dyson Heydon." The opposition has condemned the royal commission as a political witch hunt and stepped up its criticism after Mr Shorten was called to give evidence relating to deals he struck for workers as head of the AWU.

The invitation for Mr Heydon's address was first posted in April, three months before Mr Shorten's appearance. Follow us on Twitter Follow Latika Bourke on Facebook