Royal commissioner Dyson Heydon to reveal his future on Tuesday

Dyson Heydon is set to announce on Tuesday his decision about his future as the royal commissioner investigating trade union corruption.

After a morning of argument from legal counsel for the ACTU, CFMEU and Australian Workers Union that he should recuse himself on the ground of “apprehended bias”, Heydon told the hearing he would retire to consider “this interesting and in some respects complex matter”.

Heydon’s position is being challenged on the grounds he accepted an invitation to deliver the Garfield Barwick address, which was sponsored by the Liberal Party. This month he withdrew from function on the grounds that he could not address the gathering if there was “any possibility” it could be described as a Liberal Party event.

Robert Newlinds SC, appearing for the ACTU, recounted the details of emails from Gregory Burton, the organiser of the function and chairman of one of the Liberal Party’s legal branches, which repeatedly made clear that it was a Liberal Party function.

Newlinds pointed out that the test for “apprehended bias” had a “low threshold”, with a double “might”. “Might a fair-minded observer think you might not bring an impartial mind to the resolution of the issues of the commission, in circumstances where he knows that you were at all times prepared to speak at what you knew was a Liberal Party event?”

Such an observer would know the “extraordinarily highly charged public and political nature of the commission”, Newlinds said.

“He knows that this is red hot in political terms and yet, he knows that you, for a year, were quite happy to lend your name to an event of the Liberal Party … and that for a significant period this year you indeed were prepared to speak when the commission was continuing, in circumstances where you most definitely knew it was a Liberal Party function.”

Heydon has said that he overlooked both the Liberal connection and also the fact that his initial agreement to speak had been conditional on the commission being finished by the time of the address.

John Agius SC, for the CFMEU, said certain email attachments had been missing from documents provided last week. He later explained that he had just been told that in an email “chain” attachments dropped off.

Opposition Leader Bill Shorten condemned the royal commission as “always a political witch-hunt”.

ACTU secretary Dave Oliver said Tony Abbott should shut down the “farce” immediately.

What happens next?

Anna Olijnyk, Lecturer, Adelaide Law School at University of Adelaide

If Heydon steps down a new commissioner can be appointed. The problem is, the new commissioner could not simply pick up where Heydon has left off. If Heydon concludes that there is a reasonable apprehension of bias, findings he has made up to this point will be tainted by that finding.

The royal commission has been underway for 18 months. It has held almost 100 days of hearings and taken evidence from hundreds of witnesses. Last December, the commission published an 1800-page interim report.

A new commissioner would have to start from scratch. At the very least they would have to watch every second of the recorded hearings. At most they would have to recall all the witnesses. The federal government would need to think long and hard about whether to pour more resources into this exercise.

If Heydon does not step down the unions may choose to take their case to either the Federal Court or the High Court. If the unions succeed, Heydon will be removed from the commission. The court will apply the same test that Heydon is currently applying to himself: whether the fair-minded lay observer might reasonably apprehend that Heydon might not bring an impartial mind to his task.

The difference will be that, this time, Heydon will not be sitting in judgment on himself.

Michelle Grattan does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.