In a significant development, the as yet unnamed figure will also look at the minister's competence in the job.

Labor has confirmed a broad-ranging inquiry into the bullying allegations made by Mr Somyurek's chief of staff Dimity Paul last week. The government had previously suggested the inquiry would be conducted by department of Premier and Cabinet secretary Chris Eccles.

Although it remains unclear what powers the inquiry will have, it will not only examine the alleged bullying, but also the management practices of Mr Somyurek's office – including its "management practices" and "capability".

It will also consider whether Mr Somyurek's office adhered to "Victorian public sector values".

Labor Party sources have suggested the broad-ranging nature of the terms of reference could provide sufficient scope to bring into question Mr Somyurek's competence as a minister.

The examination of   "public sector values" is equivocal, with the potential to raise tough questions for political office more broadly.

Premier Daniel Andrews revealed on Saturday that Ms Paul had alleged a pattern of "intimidating, aggressive and threatening" behaviour dating back to February. Mr Somyurek has strenuously denied the allegations.

The allegations have fuelled internal Labor tensions, with suggestions the complaint was factionally motivated after Mr Somyurek's decision to defect from the right aligned Shop Distributive and Allied Employees' Association to another right-faction grouping, while Ms Paul remained.

But others dismiss such arguments, pointing out that Ms Paul's allegations are of a serious nature.

Mr Andrews on Monday refused to comment on any claims that a factional war had broken out in the party, saying he did not want to prejudice an investigation into serious allegations.

"There is an important process going on ... and I'm not going to prejudice that process by running a commentary over the top of it," Mr Andrews said.

Mr Somyurek will not be in  Question Time when Parliament resumes on Tuesday. Opposition Leader Matthew Guy revealed Labor had requested a "pair" for Mr Somyurek – who would be absent on health grounds – to ensure the balance of numbers in the upper house is maintained.

Labor MPs said they believed Mr Andrews had made  the right call to stand Mr Somyurek down from his ministerial duties while the investigation takes place.

Public Transport Minister Jacinta Allan said she was concerned to hear any allegations of   bullying.

"I think everyone deserves the right to have a safe and respectful workplace," Ms Allan said. "Any allegation should be taken seriously and that is exactly what the Premier has done."