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

Mr Heydon was initially to have made the decision by Tuesday, however late on Monday he announced in a statement that he needed more time.

Now the decision will come at 10am (AEST) on Friday.

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The Australian Council of Trade Unions, the Construction, Forestry, Mining and Energy Union (CFMEU) and the Australian Workers Union all made applications for Justice Heydon to stand down from the Royal Commission into Trade Union Governance and Corruption.

According to Monday’s release, the “Royal Commission will make a further statement on the timing of Commissioner Heydon’s decision in due course”.

A session scheduled for Wednesday involving the NSW CFMEU has also been postponed to a date yet to be fixed.

Earlier in August, it emerged Justice Heydon agreed to speak at a Liberal Party function, believing that his role as Commissioner would be finished.

Government still back Heydon, inquiry

The Federal Government has said it wants the royal commission to continue even if Justice Heydon stands down.

“I’m not going to be in a position of trying to pre-empt what he [Mr Heydon] should or should not do,” Senator Abetz said.

“We believe there is very important work for the royal commission to undertake.”

A written submission lodged on behalf of the unions said Mr Heydon should resign “on the grounds that he is unable to afford any union or any person associated with any union procedural fairness as a result of his apprehended bias”.

The submission described the royal commission as “politically charged”. It said a fair-minded observer could reasonably believe the commissioner might not bring an impartial mind to issues before the commission.

Opposition Leader Bill Shorten, who was himself called to appear before the commission, said he would not block moves to appoint a replacement if Justice Heydon did rule himself out.

The Abbott Government has stood behind Justice Heydon and defended his integrity.

– with AAP and ABC