Dyson Heydon to reveal his fate on Friday

Royal commissioner Dyson Heydon will hand down his decision on Friday over union applications for him to stand down over perceived bias.

Dyson Heydon's decision about his future as royal commissioner should be respected, the PM says. (AAP)

Dyson Heydon will reveal on Friday morning whether he will disqualify himself as royal commissioner overseeing the inquiry into trade union corruption.

In a statement, the commission said Mr Heydon would announce his ruling on Friday at 10am AEST.

His decision comes a week after the ACTU, CFMEU and AWU made submissions seeking the commissioner stand aside over perceived bias, because he accepted an invitation to speak at a Liberal Party event.

Mr Heydon has been considering his position, having already admitted he "overlooked" the connection to the political party when he agreed to give the Sir Garfield Barwick address.

The event was meant to be held on Wednesday night.