The United Firefighters Union, a political thorn in the side of the Andrews Labor government for much of its tenure, sounded an ominous warning on Wednesday that fresh trouble had arrived.

The union’s Victorian leader says the man chosen for the MFB's top job, Englishman Dan Stephens, has a “union-busting, budget-breaking” track record in his previous job as fire chief in the northern English city of Liverpool.

Within hours of the news of Mr Stephens’ appointment to the MFB on Wednesday, the union’s combative branch secretary Peter Marshall was on the attack, saying the former chief officer of the Merseyside Fire Brigade had presided over savage cuts to firefighter numbers in the city.

Mr Marshall also alleged that fire deaths in the Liverpool area had doubled during Mr Stephen’s tenure.

But according to the Liverpool Echo newspaper, Mr Stephens was known for his fierce opposition to government-imposed budget cuts.

And both the MFB and Emergency Services Minister James Merlino said on Wednesday that their new man had a strong record of advocating for his workforces.

MFB board president Jasmine Doak said that Mr Stephens had a wealth of experience in firefighting, emergency services and with unions.

"Dan has a great relationship with the [Fire Brigades Union] in the UK at the moment, he works in a unionised workforce and he knows how important that is," Ms Doak said,

"He will build all the relationships he needs once he gets here."

Mr Marshall, who will gather his members on Monday for a large meeting to discuss the new appointment, indicated the new chief officer might have a challenge on his hands, with the union leader telling his members that Mr Stephens was bad news for Melbourne firefighters.

“The UFU has serious concerns about the appropriateness of the appointment as we do not want to import the British fire services culture of forfeiting safe working conditions and firefighter positions for pecuniary purposes,” the union leader wrote in his bulletin.

Mr Marshall had a clear warning to the Andrews’ government that there was trouble coming if it persisted with hiring Mr Stephens.

“We are surprised that a Labor Andrews government would support the appointment of Mr Stephens who has reportedly been party to union-busting tactics,” Mr Marshall wrote.

“This is a low point for union relations with the Andrews Government and will be a defining moment in the short and long term relationship.”

But Mr Merlino said Mr Stephens had been a fighter for the rights of the workforce on the Mersey brigade.

“Mr Stephens is ... a strong advocate for the rights of firefighters, improving the safety of the community and fighting against government budget cuts in his role at the helm of the Merseyside Fire Rescue Service," the minister said.

“We have always been determined that a wide-ranging search would be undertaken to find the best possible candidate for this important role.

"A key part of Mr Stephen's role will be to rebuild the relationship between management and the MFB workforce."