A union has called for the dismissal of Victorian Health Minister Jenny Mikakos, accusing her of “breathtaking incompetence”.

A Health Workers Union letter to Premier Daniel Andrews urging her removal was made public on Thursday, hours before Ms Mikakos appeared before the inquiry into Victoria’s hotel quarantine program, which led to the state’s devastating second wave of coronavirus.

“Sadly, our union’s relationship with your government is now officially dead, due solely to the breathtaking incompetence of your current Health Minister,” HWU Secretary Diana Asmar wrote.

“For the good of all Victorians, and health workers, I ask that you insist on Ms Mikakos’ resignation, effective immediately.”

Tweet from @Health_Workers

Ms Mikakos’ appearance at the inquiry followed fellow ministers Lisa Neville and Martin Pakula, who claimed the Department of Health and Human Services was in charge of the program.

Their evidence on Wednesday contrasted that of DHHS secretary Kym Peake, who told the inquiry there was “shared accountability”.

While Mr Pakula’s Department of Jobs, Precincts and Regions was tasked with contracting hotels and security companies for the program, he said the DHHS held “overall responsibility”.

Neither he nor Ms Neville, who is police and emergency services minister, knew who made the decision to use private security in the program.

Ms Neville said the issue “didn’t jump out” immediately, noting contractors were used at parliament, hospitals and police headquarters, as well as for major events.

“Reflecting on the question now, there are clearly things that went wrong,” she wrote in her submission to the inquiry.

“I do not know whether that was because of the use of private security at all or because of issues with the management and oversight of the private security arrangements, infection control management or both.”

More than 30 staff and guards working at two quarantine hotels – the Rydges on Swanston and Stamford Plaza – caught COVID-19 from returned travellers and spread it into the community.

It was also revealed Ms Peake and her deputy Melissa Skilbeck denied a request from Mr Andrews to house passengers from the Greg Mortimer cruise ship at a hotel near the airport.

Eighty of the passengers were COVID-positive.

“Premier has also requested that we use a hotel that is close to the airport, not in the CBD,” Ms Peake wrote in an email on April 9.

Ms Skilbeck replied: “At this late stage of planning it would be risky to seek to convince another hotel to contract to take such guests.”

The passengers were sent to the Rydges on Swanston.

Ms Peake also failed to brief Ms Mikakos on two Safer Care Victoria investigations that identified problems with the program.

Mr Andrews will appear before the inquiry on Friday afternoon in its final week of public hearings.

-AAP