Forty past and present coalition MPs will be referred to Victoria's Ombudsman over the possible misuse of public funds in connection with convicted embezzler and former Liberal director Damien Mantach.
The Labor government plans to refer the MPs as it ramps up counter-attacks to its $388,000 rorts-for-votes scandal which is the subject of police and parliamentary inquiries months away from a state election.
Deputy Premier James Merlino told parliament on Tuesday that he will refer the Liberal-Nationals coalition MPs, including Opposition Leader Matthew Guy, plus former premiers Denis Napthine and Ted Baillieu, over the Mantach case.
"Did anyone else benefit from this $1.5 million fraud? These were dodgy, inflated invoices," Mr Merlino told reporters outside parliament.
"It is fair that everyone in this parliament is subject to the same scrutiny, if the Labor party is going to be subject to this scrutiny, it is fair and right that the Liberal Party and the National Party are also subject to the same scrutiny."
Mantach stole more than $1.5 million from the Liberal Party using fake and inflated invoices.
His scam included a mailing business inflating invoices to Victorian Liberal MPs and the party eventually repaid nearly $200,000.
"The Liberal Party referred Damien Mantach in 2015, he was charged with serious offences and he went to jail as was correct," opposition spokesman Tim Smith told reporters.
"Unlike the Labor Party who has spent millions of dollars and the last three years trying to block the ombudsman's investigation all the way to the High Court, lower house MPs including the premier have refused to take part in that investigation."
Mr Smith said there was "absolutely" no evidence any MP benefited from Mantach's fraud.
The government's move came after Mr Merlino referred 18 current and former coalition MPs to police last month over whether they used electorate staff for political campaigning at the 2014 election.
Both parties continue to trade barbs as Labor's rorts-for-votes scandal continues, with the opposition calling the government "crooks" across the lower house chamber.
As the police probe continues, the opposition has called for six ministers involved to stand down and for the government to secure bipartisan support for major government decisions.
Mr Andrews on Tuesday rejected the proposed caretaker model.
During the latest sitting of a parliamentary inquiry into the Labor scandal, senior bureaucrat Peter Lochert denied previous evidence from scheme architect John Lenders that the pair met and workshopped the plan.
Ombudsman Deborah Glass in March found 21 past and present Labor MPs breached parliamentary guidelines by directing staff employed as electorate officers to campaign for candidates.
Seventeen former campaign staff across Victoria, NSW and the Northern Territory were last week arrested and interviewed as part of the fraud probe but no charges were laid.
Labor has since repaid the $388,000.