Five weeks after Premier Daniel Andrews launched an investigation into claims against Small Business Minister Adem Somyurek, concerns have been raised about backroom attempts to denigrate his accuser and dismiss her allegations as little more than factional payback.

Mr Somyurek was stood down from cabinet after his chief-of-staff, Dimity Paul, accused him of a pattern of threatening and intimidating behaviour, suggestions the upper house MP strenuously denies.

In a strongly-worded statement obtained by The Sunday Age, several groups and individuals have raised concerns about Ms Paul becoming the subject of anonymous backgrounding to the media.

"There is no place for victim-intimidation in bullying complaints," the statement said.

"Women everywhere need to be confident that, should they muster the courage to ever raise concerns about the workplace behaviour of their supervisor, whether they're their manager or their minister, those concerns will be dealt with on their merits and their character not impugned through media."

Signatories to the statement include former women's minister Mary Delahunty; former equal opportunity commissioner Moira Rayner; councillors Meghan Hopper and Casey Nunn; well-regarded Labor women Hutch Hussein and Lori Faraone; and former chief executive of the No To Violence campaign, Danny Blay.

Their views were backed by Domestic Violence Victoria chief executive Fiona McCormack, who questioned what kind of message it sent when women were "denigrated" for speaking up in the home or workplace, and Liberal upper house leader Mary Wooldridge.

"When women speak out about issues concerning their safety in the workplace, they put their reputations, financial security and future employment options at risk," Ms McCormack said.

Ms Wooldridge told The Sunday Age: "Daniel Andrews says he is the champion of addressing violence against women, but when faced with claims of abuse the Labor Party are instead vilifying the woman who dared to raise legitimate concerns."

The comments come as the investigation into Mr Somyurek runs into its fifth week, with no certainty on when it will finish or whether the full findings will be made public.

While both parties are under strict instructions not to speak publicly while an inquiry by former judge Michael Strong is underway, Mr Somyurek's supporters said  Ms Paul's claims were payback for a split within the Right that weakened the influence of the shop assistants' union, of which she and her husband remain members.

A front-page article in the Saturday Herald Sun last week, in which anonymous sources portrayed the 28-year-old chief of staff as an "ambitious" woman who had actively undermined her boss by criticising him to others, prompted several in the Labor Party to speak out.

The signatories on the statement - which included Domestic Violence Victoria, EMILY's List, YWCA Victoria, and the Women's Information and Referral Exchange - said they did not wish to prejudice the investigation, but wanted to highlight the "message of intimidation that such cowardly allegations sends to bullying complainants everywhere".

"It is sad that we have not learnt anything from the treatment of our first female premier nor our first female prime minister," the statement said.

"Women are allowed to be ambitious, women are allowed to pursue careers in politics and women are allowed to expect a high standard of the people they work with."