The barrister representing the ACTU, Robert Newlinds expressed concern that he had not received all relevant documents on Monday as promised. Dyson Heydon is facing calls to stand aside as head of the trade unions royal commission. "Boy, you've got to be confident when you tell someone that they've got all the documents and you were wrong when you told me that, and there's no explanation for how that could have happened," Mr Newlinds said. Unions and Labor are urging Mr Heydon to stand aside from the inquiry because of an alleged appearance of bias after he accepted an invitation to a Liberal Party fundraiser, the Garfield Barwick lecture to be held in Sydney next week. The hearing has been adjourned until Tuesday when a decision is expected to be made. Mr Agius said earlier he was concerned that the information released on Monday was "at best a partial disclosure, if not a disclosure of a doctored document which had been edited to remove the reference to state donation".

The full email "makes clear that connected with the invitation to the Barwick lecture was a state donation compliance requirement which clearly identifies the function as one which might be called a fundraiser". In response to a union request for all documents relating to the fundraising event, Mr Heydon on Monday released emails he received from Gregory Burton, the chair of professional engagement for a lawyer branch of the NSW Liberal Party. The CFMEU received the full contents of the email on Thursday and said it was "misleading" for the complete document to have been concealed. Mr Agius said a fair-minded observer would have "serious concerns" about the omission and was "very likely to find that if you Mr Commissioner were willing to speak at the Liberal Party function that you were also aware of the consequences of publicly portraying your position as such". Mr Agius also accused Mr Heydon "contrary to denials" of becoming aware of the Liberal Party event as a fundraiser following the receipt of the email in August.

Senior counsel assisting the royal commission, Jeremy Stoljar, said solicitors for the CFMEU were given at their request an electronic copy of all emails. "That electronic copy should have been produced to the solicitors for the ACTU and the AWU. By oversight of commission staff it was not, that was an error," he said. "However, while not excusing the error, firstly, it is clear from the face of the email that the invitation was enclosed or attached and secondly, copies of the email and the invitation were in evidence on Monday. All that was missing was the stand alone version of the email. "There is no basis whatsoever for the serious allegation that the version …produced by commission was altered or doctored in any way." Earlier on Friday morning, Mr Newlinds put a case of alleged apprehended bias to Mr Heydon based on what he said was the former High Court judge's willing association with a Liberal Party event.

"Our submission is that in agreeing to do the speech... is such as to associate yourself with the Liberal Party. And if I can put it bluntly, people don't speak at fundraisers of a political party unless they believe in the cause of that party, and they certainly don't speak at fundraisers of a political party if they support the other side of politics," Mr Newlinds said. "I only think the hypothetical observer would think that you harbour a political prejudice." Mr Newlinds said the result of the inquiry "will have no credibility to anyone if it comes forward in the context that there's a finding that it was a biased hearing". He said if the report was to be used for a beneficial purpose "it has to be unimpeachable and it can't be allowed to happen that people can just walk around after reform and say don't worry about that report, that was old Mr Heydon". Mr Heydon has been under growing pressure to step aside since Fairfax Media revealed he accepted an invitation last year to give the keynote speech at event.

Mr Heydon said he "overlooked" the Liberal Party connections to the event and cancelled his appearance last week after he realised it was a fundraiser. He said he had not read an attached donation form and flyer he received in June. Mr Heydon will consider the union applications for him to disqualify himself on the grounds of alleged apprehended bias. Mr Stoljar said a royal commissioner must act in accordance with the rules of natural justice. "One of the rules of natural justice is the rule against bias," he said. That bias can be actual, needing to meet a high threshold or apprehended, requiring a lower test.

Unions have made an application based on apprehended bias which carries the test of whether a "fair-minded lay observer might reasonably apprehend that the judge might not bring an impartial and unprejudiced mind to the resolution of the question he or she is required to decide". A judge should not disqualify himself or herself on the ground of bias or reasonable apprehension of bias unless "substantial grounds are established", Mr Stoljar said. Mr Heydon has received applications for him to recuse himself from the inquiry by the ACTU on behalf of the Health Services Union, Transport Workers Union, Unions NSW, the Maritime Union of Australia and the Communications, Electrical and Plumbing Union. The CFMEU and the Australian Workers Union have made their own submissions. ACTU secretary Dave Oliver has said the ACTU was seeking Mr Heydon's disqualification of himself because the Prime Minister Tony Abbott had refused calls to shut down the inquiry.

Mr Heydon said he was approached on April 10 last year to give the keynote speech. He said he would be "amenable" to delivering the address if the royal commission had finished its work. The commission was due to deliver its final report in December last year but in October last year, the deadline was extended by 12 months. "[I]n March 2015, I overlooked the connection between the person or persons organising the event and the Liberal Party which had been stated in the email of 10 April of 2014," Mr Heydon explained on Monday. "I also overlooked the fact that my agreement to speak at that time had been conditional on the work of the commission being completed before that time." Mr Burton's email of April 10, 2014 declared the lawyer branch is formally a branch of the Liberal Party, but its aim was to be a "liberal-minded bridge to the profession rather than overtly party political. (Although we trust we show the party in a favourable light!)," the email said.

When he explained the background in the royal commission on Monday, Mr Heydon said the April 10 email "did not state and I did not understand from it that the Sir Garfield Address was in any sense a fundraiser for the Liberal Party". Mr Heydon said he did not think about the address again until he was reminded of it in March this year when he was working at Oxford law school. He had planned to give a speech on "the judicial stature of chief justice Barwick viewed in a modern perspective". "I planned to analyse the general nature of the High Court and its methods of operation under him," Mr Heydon said. In response to another email he received on August 12, Mr Heydon's personal assistant said: "If there is 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". "Shortly after the dispatch of that email it was made plain that I would not be giving the address." Mr Heydon said.

"My understanding at all times has been that the dinner was not to be a fundraiser." Unions are leaving open the option of appealing any of the royal commission's findings in the High Court. Follow us on Twitter