How the deadlock was broken by the Premier,Mr Bates and Mr Marshall,and whether it involved any improper conduct,is one of the strands of the IBAC investigation.

The Age has also confirmed that in addition to interviewing former and serving Labor MPs and staffers about the deal,IBAC investigators have seized mobile phones,laptops and dozens of USBs belonging to the UFU or its secretary,Mr Marshall. Among those interviewed this year by IBAC are former members of the Premier’s inner circle.

Mr Andrews said on Tuesday that,“in my experience and in my judgment” Mr Bates had always acted with integrity in his interactions with Mr Marshall and the union.

“That’s not a matter for me to determine,” he said. “I’ve been very clear over all my time in public life that integrity agencies should have the full support of the government and every member of it.” In certain circumstances,it may be an offence for a person to comment on IBAC’s activities.

Mr Bates,a deputy secretary in the Education Department,declined to comment when contacted byThe Age. Mr Marshall did not respond to repeated messages.

Two former members of Mr Andrews’ inner circle said there was nothing to suggest the Premier had acted inappropriately and queried whether IBAC had a place scrutinising political and industrial negotiations. Some serving members of Mr Andrews’ cabinet who spoke toThe Age this week said lack of transparency about the Premier and Mr Bates’ dealings with the UFU raised probity issues,but others were dismissive of suggestions that any such dealings had reached the level justifying an adverse finding by IBAC.

A second investigative strand of the IBAC inquiry involves dealings between Mr Marshall and Animal Justice Party MP Andy Meddick,whose vote helped pass the union-backed fire services reform legislation after his child was given a two-week paid placement at the UFU.

When asked last year if the Premier had knowledge of Mr Meddick’s child getting a short-term job at the union,a government spokesman said:“None whatsoever.” Mr Meddicklast year toldThe Age he had voted on the fire services reform based on “my values,party policy,my trade union background and consultation with many firefighters across the state”. Mr Meddick also said the job had been awarded to his child on her merits.

He said he had declared his position on the bill to Mr Marshall “well before” it was debated in Parliament and to the government soon after he was elected in 2018.

The Independent Broad-based Anti-Corruption Commission has extraordinary powers of investigation,but under commissioner Robert Redlich has generally adopted a cautious approach in publicly airing details of its investigations.

This is especially so given the grey area that can surround government deal-making with unions and conduct that does not involve explicit “brown paper bag” corruption,but rather issues of public trust and use of official power. In the case of the UFU’s dealings with the Andrews government,the issues under investigation involve questions around the appropriate use of political power and the transparency of closed-doors negotiations held to strike a deal that may have benefited the UFU and Labor but at a cost that may have been ultimately borne by the taxpayer.

In contrast to the corruption commission inquiry that led to the resignation on Friday of former NSW premier Gladys Berejiklian,there is no suggestion that Mr Andrews has not disclosed a personal interest. Unlike the case of the former NSW Premier,IBAC has given no indication it intends to hold public hearings or spelled out that it is probing adverse allegations involving Mr Andrews.

The IBAC investigation into the UFU’s dealings commenced in mid-2019 and it has been stalled on multiple occasions by legal challenges,the nature of which are suppressed.

“As a matter of practice,IBAC does not comment on whether it has a complaint or investigation before it,” an agency spokesperson said this week.

It has previously been reported in media outlets that Mr Marshall claimed that Mr Andrews had made pre-election commitments to the UFU that may not have been disclosed publicly. Mr Marshall insisted that Mr Andrews needed to honour these commitments.

Among the outcomes of the dealings between the UFU and the Andrews government was the fire services reform bill. The bill passed Parliament in 2019 after 4½ years,and claimed the scalps of one minister,Jane Garrett,and two fire chiefs,Lucinda Nolan and Joe Buffone.

The Andrews government also sacked the entire Country Fire Authority (CFA) board in 2016 at the height of tensions.

The legislation enabled the CFA’s 1220 brigades to become volunteer-only and stations with career firefighters to merge with the Metropolitan Fire Brigade,to become known as Fire Rescue Victoria. The move was seen by volunteer firefighters and the Victorian opposition as a union power grab.

Little information about the IBAC investigation,apart from the fact it is ongoing,has been made public since it commenced in early 2019. Over several weeks,The Age has pieced together the most complete picture of the IBAC inquiry.

The anti-corruption agency can only move an investigation from preliminary phase to a full-blown probe if it believes the allegations it has received about misconduct are not frivolous or vexatious and involve the dishonest use of power.

It has jurisdiction over those members of the UFU who are employees of the state fire services body,which makes them public servants. Members of Parliament are also subject to IBAC’s jurisdiction.

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