Victoria's Emergency Management Commissioner Andrew Crisp and Victoria Police Chief Commissioner Shane Patton are due to front a public accounts and estimates committee hearing on Wednesday, where they will be questioned about the state's botched hotel quarantine program.

A committee hearing earlier this month heard that the hotel quarantine system, including the use of private security guards, was signed off by Mr Crisp under advice from a "governance group" made up of bureaucrats from the Department of Health and Human Services, Department of Jobs, Regions and Precincts, Victoria Police, Department of Transport, and Department of Premier and Cabinet.

Mr Crisp has not spoken publicly on the issue, except when he released a statement on August 12 saying the Australian Defence Force was part of planning and co-ordination meetings for the quarantine program on March 27 and March 28, but no personnel assistance was offered.

"During these discussions, I did not seek nor did representatives of the ADF offer assistance as part of the hotel quarantine program," Mr Crisp said.

Genomic sequencing by Melbourne's Doherty Institute shows 99 per cent of Victoria's second-wave cases may be traced back to quarantine breaches at two quarantine hotels.

Ms Mikakos also addressed the government's plan to extend Victoria's state of emergency by 12 months.

She acknowledged public anxiety over the move, but indicated the government would not reduce the timeframe in order to win parliamentary support for the change.

The minister said the 12-month plan would allow the government to continue extending the state of emergency in four-week increments over the coming year as required, under the advice of health experts.

The extension would have no bearing on the length of Victoria's current lockdowns, she said, but would allow the government to continue making measures such as wearing face masks in public and COVID-safe work plans mandatory.

The Andrews government does not have an upper house majority and faces a tough fight to win enough support from crossbenchers to get the extension through.

"I understand people are anxious and we will work incredibly hard to make sure people understand that this is an insurance policy," Ms Mikakos told Radio National.

"We will have a debate in Parliament next week. I've been having conversations with crossbench MPs over the last few days.

"We think that MPs should respect public health experts … [who say] a vaccine is unlikely in the next few months … So we need these measures in place to protect us until such time as we have a vaccine."