The Public Health and Wellbeing Amendment (Pandemic Management) Bill faces defeat in the upper house after former Labor MP Adem Somyurek declared he would return to parliament to vote against it.

The government had been relying on his absence and the support of three crossbenchers - the Greens' Samantha Ratnam, Reason Party MP Fiona Patten and Animal Justice Party MP Andy Meddick - for an amended version of the bill to pass.

But a no vote by Mr Somyurek would result in a tie, meaning the bill would have to be reintroduced in parliament's lower house.

The government successfully delayed the debate in the upper house on Thursday morning.

Attorney-General Jacyln Symes said the government needed to delay debate on the bill so it could provide Mr Somyurek with a briefing.

The bill gives the premier the power to declare a pandemic and the health minister the ability to enforce restrictions such as lockdowns, mask-wearing and vaccination mandates.

But it has become a lightning rod for anti-lockdown and anti-vaccination groups who have occupied the steps of state parliament this week in protest.

Without the legislation, the government won't be able to impose many of its COVID-19 restrictions after the state of emergency expires on December 15.

Unlike other jurisdictions, Victoria's state of emergency cannot be extended indefinitely.

Ms Symes has been busy hitting the phones to garner the support of an additional crossbencher.

AAP understands the government has since had constructive conversations with crossbench MPs about the bill, which will continue into the evening, and debate is likely to resume on Friday.

Sustainable Australia MP Clifford Hayes flagged he would talk with the Andrews government after initially being ignored for months.

"What we're seeing today is a problem that's entirely of the government's making," he said.

"If they want our support, it has to have proper checks and balances."

He has called for tougher oversight of pandemic powers, noting the bill in its current form allows only for the Labor-led Scrutiny of Acts and Regulations Committee to examine orders.

"It's got to have proper parliamentary oversight and independent oversight as well," Mr Hayes said.

Premier Daniel Andrews conceded the return of Mr Somyurek meant the government did not have the numbers for the bill to pass.

"We don't have the numbers in the upper house, we'll just do our normal thing which is to work with everybody and try and get an outcome that keeps us safe," he told reporters.

He said he did not know if the matter would get resolved on Thursday or Friday.

If the government fails to reach an agreement with the crossbench this week, it only has another three sitting days to resolve the impasse this year.

Mr Somyurek has only been at parliament twice since he was forced out of the party in June 2020 for leading a branch-stacking operation.

In an opinion piece penned for the Herald Sun, he said the proposed laws give too much power to the state government and its leader, and lacks independent oversight and "appropriate mechanisms" to scrutinise the new powers.

Ms Patten described his return as "revenge" to the Labor party for dumping him.

Victorian Opposition Leader Matthew Guy said he was happy to consult with the government to "get a sensible piece of legislation through the parliament".

Australian Associated Press