Dyson Heydon to reveal his commission fate

WHAT WILL ROYAL COMMISSIONER DYSON HEYDON DO?

THE BACKGROUND

* Former High Court judge Dyson Heydon was appointed by the coalition government to oversee the Royal Commission into Trade Union Governance and Corruption in March 2014.

* In April 2014 he accepted an invitation to give the August 2015 Sir Garfield Barwick address.

* On August 13 this year he pulled out after realising it was organised by the Liberal Party and a fundraising event.

* He has since admitted he "overlooked" the connection to the Liberal party and the timing of the speech.

* Unions and federal Labor want Heydon to stand down and have applied for him to disqualify himself.

WHAT THE UNIONS ARGUE

* ACTU (on behalf of other unions), CFMEU and AWU have made separate submissions seeking to have Heydon disqualified.

* They claim an average person would think the commissioner would not bring an impartial mind to proceedings, having been willing to speak at a Liberal Party fundraising event.

* Heydon couldn't give unions or other witnesses before the commission a fair hearing because of a perceived political bias, they say.

WHAT DYSON HEYDON HAS TO DO

* Heydon is making a decision on his own future as commissioner.

* Unions wanted him to put himself in the shoes of a "fair-minded" observer when coming to his decision.

* He has spent more than a week considering what he describes as an "interesting and in some respects complex matter".

* His decision will be revealed at 2pm AEST, Monday, August 31.

WHAT WILL HAPPEN NEXT

* The federal government has indicated it wants to continue with the royal commission regardless of what Heydon decides.

* The commission, which was extended late last year, is due to hand down its final report by December 31.

(Source: Royal commission website)