Union boss Peter Marshall claims a deal was struck and has threatened to reveal the details before the November state election.

"We made election commitments all of which are public and well known," Mr Andrews told reporters on Thursday.

When asked if there was any material, including a secretly recorded tape, that the union has been using to blackmail the government, Mr Andrews replied "no".

The premier also said he does not "have a need to speak" to Mr Marshall.

The union official would not confirm if he had a recording of Mr Andrews, but told ABC Melbourne on Wednesday deals were done.

"There was a number of promises and they'll come out in the near future," he said.

Mr Marshall came out swinging against the appointment of new Metropolitan Fire Brigade chief Dan Stephens from the UK, calling him an "attack dog against the union".

The war of words is the latest blow-up in the government's bid to reform the state's fire services, nearly two years after Mr Andrews vowed to fix them.

But the premier said he is not frustrated by the union.

Opposition Leader Matthew Guy called the situation an "unedifying spectacle".

"If the government made a pre-election deal with the firefighter's union, well Victorians deserve to know how much it's worth and what the deal involved," he told reporters.

The MFB and Country Fire Authority have been locked in bitter, protracted pay disputes with the union for years, resulting in former emergency services minister Jane Garrett resigning, the CFA board being sacked and other officials departing.

It became a federal election issue and the Turnbull government made the CFA pay deal illegal, prompting the state government to try and make it a volunteer-only service while creating a new, expanded professional fire brigade.

But that legislation came to a spectacular end on Good Friday, when two opposition MPs who had asked to be excused from the final parliamentary vote for religious reasons, came back into the chamber and voted down the bill.

Australian Associated Press