A royal commission into trade unions has heard fresh allegations of a culture of bullying, harassment and intimidation within the Health Services Union (HSU).

The Royal Commission into Trade Union Governance and Corruption has so far focused on the affairs of the union's number 3 branch in Victoria between 2003 and 2010, but has now turned its attention to the conduct of officers in the number 1 branch.

The hearing was told Marco Bolano and Diana Asmar ran for the position of branch secretary in late 2012.

Ms Asmar won the vote, but the role of assistant secretary went to Leonie Flynn, who ran on Mr Bolano's ticket.

What followed was a period of tension between the two office holders, with Ms Flynn alleging she was threatened by Ms Asmar.

Counsel assisting the commission Jeremy Stoljar SC said he had received damning evidence.

"They raise allegations against Ms Asmar of breaches of union rules and a culture of bullying, harassment and intimidation," he told the hearing.

Mr Stoljar said the role of assistant secretary "carries with it significant responsibilities", including management of financial affairs.

Ms Flynn said Ms Asmar obstructed her from performing her required duties by threatening to "have the rules changed" through the branch committee of management "for her to have financial control".

The commission has also heard allegations concerning Ms Asmar's approach to Right of Entry Permits.

The permits were issued by the Fair Work Commission and allow the holder to enter and remain on an employers' premises.

HSU staffer 'deeply uncomfortable' with carrying out instruction

Applicants must undertake training and sit an online test, but the hearing was told Ms Asmar instructed other members of staff to sit the tests "on behalf of other employees and organisers".

One of those staff members, Peggy Lee, has told the commission she carried out the instruction despite being "deeply uncomfortable" with it.

"Because of the pressure I felt I was under while at the branch, I actually completed Right of Entry tests for other people knowing it was wrong to do so," her statement to the commission read.

The Fair Work Commission was also investigating the matter after it received a complaint in September 2013.

Ms Asmar is expected to give evidence tomorrow.

She released a statement saying the allegations of wrongdoing and bullying against her were false and had been made by people with ulterior motives.

She said the claims were made by people with an election agenda and she was looking forward to setting the record straight when she fronted the inquiry.

Outside the commission she denied the claims.

"Are you a bully?" a journalist asked.

"Definitely not. Look forward to proving they're lies," Ms Asmar said.

Mr Stoljar said the branch went through "fraught and bitter" times between 2006 and 2009, when Jeff Jackson held the position of branch secretary.

Mr Jackson is the ex-husband of HSU national secretary Kathy Jackson.

Ms Flynn is currently on leave from her position as assistant secretary of the branch.

Kathy Jackson to appear again at commission

During the last hearing in July, the royal commission questioned Ms Jackson about a slush fund account in which members' money was allegedly used to pay off her personal credit cards.

The National Health Development Account (NHDA) was first set up in 2003 with a $250,000 payment from the Peter McCallum Cancer Institute.

The commission has been told that until 2010 funds from the number 3 branch bank account were transferred to the NHDA "on Ms Jackson's instructions".

Ms Jackson told the July hearing she could not recall details about a $50,000 payment she authorised from the NHDA.

She asked for legal representation when pressed about the matter by Mr Stoljar.

Mr Stoljar produced evidence that the money was paid to Mr Jackson and asked her why she did not disclose that.

Ms Jackson told the commission she had been "ambushed".

Ms Jackson is one of 24 witnesses expected to give evidence in Sydney in this latest hearing and will appear later this week.

The HSU is one of five unions being scrutinised by the Royal Commission into Trade Union Governance and Corruption.