A no-confidence motion is hanging over the Victorian government as the state's rorts-for-votes scandal widens with the opposition also facing possible investigation over its activities.
Opposition Leader Matthew Guy gave notice of his motion at the start of parliament on Wednesday.
"This government is behaving like a circus," he told reporters.
"It is not governing for Victoria, it is not focusing on crime, congestion, cost of living."
"The fact that six ministers, having been named in the ombudsman's report, 21 Labor MPs as well - this whole tawdry affair being investigated now by the fraud and extortion squad, these ministers not standing down, as unprecedented as it is, has warranted this motion to be moved."
The motion will be debated on August 22 but the government has the numbers in the lower house to quash it.
Late on Wednesday an opposition bid to have six government ministers step aside over their links to the scandal was defeated 22-16 in the upper house.
It comes amid an increasingly hostile fight between the major parties over Labor's rorts-for-votes scandal, in which it misused $388,000 of public funds for campaign staff at the 2014 election.
The government has also tried to throw claims of rorting at the opposition.
It intends referring 40 past and present Liberal-Nationals MPs to Ombudsman Deborah Glass alleging potential knowledge of or inappropriate involvement with embezzler and former Liberal director Damien Mantach.
"That fraud could not have happened without the participation, the involvement, the signature of Liberal Party members," Deputy Premier James Merlino told the Legislative Assembly.
"Every single member of those opposite need to answer to the ombudsman and face the scrutiny of her office. The time for running away is over."
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.
Mr Merlino's move comes after he referred 18 current and former coalition MPs to police last month over whether they used electorate staff for political campaigning at the 2014 election.
Ms Glass in March found 21 past and present Labor MPs breached parliamentary guidelines by directing staff employed as electorate officers to campaign for candidates.
Ahead of the November 24 state election, police announced they would launch their own investigation into Labor and subsequently arrested 17 former campaign staff across Victoria, NSW and the Northern Territory.
No charges have been laid and Labor has repaid the $388,000.
The Greens, meanwhile, have used the mudslinging to call for a parliamentary referee.
"This parliament has been marred by entitlement scandals and establishing an independent body to restore the public's faith in politics is well overdue," leader Samantha Ratnam said in a statement.
"The Independent Parliamentary Standards Commissioner must be established now to ensure the next state parliament is free from scandal and public funds are used to benefit the people of Victoria."