Senior cabinet minister Christopher Pyne says the controversy surrounding Dyson Heydon is the "greatest storm in the teacup in years" but has questioned why the head of the royal commission into union corruption was asked to address a Liberal Party fundraiser.
Labor is demanding the royal commissioner quit after Fairfax Media revealed he agreed to deliver the Sir Garfield Barwick address – an event organised by the NSW Liberal Party's legal fraternity.
Opposition Leader Bill Shorten on Friday called for the release of Mr Heydon's text messages and emails relating to the event, suggesting there was more to be revealed.
But Prime Minister Tony Abbott and Attorney General George Brandis are standing by Mr Heydon and said the decision to cancel his planned appearance was the correct one.
The NSW Liberal Party says the event should not be considered a "significant fundraiser" because it only made $239 in 2014.
The official invitation includes the Liberal Party's logo and calls for donations if people could not attend. The flyer states: "All proceeds from this event will be applied to state election campaigning".
But Mr Pyne said the blame rests with the organisers, not Mr Heydon.
"Why he was invited in the first place is beyond me," Mr Pyne told Nine's Today program on Friday.
"Dyson Heydon behaved appropriately throughout the entire process, why a barrister in the Liberal Party thought it was a good idea to invite him is beyond me."
Mr Pyne said it would be a "complete overreaction" for Mr Abbott to sack the royal commissioner.
"This is a greatest storm in the teacup in years," Mr Pyne observed.
NSW Liberal Party Director Tony Nutt said in a statement that the invitation was extended to Mr Heydon "several years ago".
Mr Shorten was called before the royal commission in July to answer questions about his conduct as the former head of the Australian Workers Union.
On Friday he said whether the event raised much money was not the point.
"Many Australians will see the fact that Mr Heydon was billed to speak at a Liberal fundraiser as a smoking gun of political bias," Mr Shorten told the ABC.
He called for the immediate release all correspondence between the Liberal Party and Mr Hedyon relating to the event.
"Emails, SMS messages, diary entries and if the commission refuses to do so I think that even becomes another test for Mr Abbott," Mr Shorten said.
Mr Heydon on Thursday released two emails sent during the week, which showed he took nearly 24 hours to cancel his appearance despite being told it was a Liberal Party event.
"This event has been weeks, months in the making and there is more to be revealed here and we should see it," Mr Shorten said.
Assistant Treasurer Josh Frydenberg has also agreed the fresh political row was a distraction for the government.
