A motion to probe accusations Victorian Labor MPs told an independent auditor to "find dirt" on the state's corruption watchdog has been blocked with an 11th-hour deal.
The Victorian government is defending an about-face on changing the make-up of a powerful integrity committee to block a probe into alleged interference with the corruption watchdog.
A motion to establish a parliamentary inquiry into accusations Victorian Labor MPs told an independent auditor to "find dirt" on the Independent Broad-based Anti-corruption Commission has been effectively killed off.
In return for opposing the motion, the Greens and Legalise Cannabis Party secured a guarantee from Labor that the Integrity and Oversight Committee (IOC) will no longer have a government majority or government chair.
Former IBAC Commissioner Robert Redlich wrote to parliament's Speaker and President last year with complaints about the Labor-majority committee.Â
Mr Redlich said Callida Consulting, which was hired to audit the agency, was directed by Labor members of the IOC to "find dirt on IBAC and data that is not readily publicly available".
He called for the committee not to be chaired by a government member or have a majority of government MPs.
Greens MP and committee member Tim Read said the inquiry would have generated headlines and recommendations but was unlikely to lead to action.
"So we've gone for a bird in the hand rather than several in the bush," he told reporters at parliament on Wednesday.
Under the deal, Legalise Cannabis Party MP Rachel Payne will be added to the committee on Wednesday to give it eight members and the non-government chair would cast the deciding vote if split 4-4.
Dr Read said he would nominate to be elected chair but declined to pre-empt whether the committee would launch an inquiry into Mr Redlich's accusations.
Shadow Attorney-General Michael O'Brien claimed Dr Read's appointment as chair was part of the deal and urged him to initiate an inquiry as his first order of business.
"The very first test (of) whether the Greens have actually been bought by Labor or are simply rented is going to be whether or not this inquiry goes ahead."
The opposition's upper house leader Georgie Crozier said their motion will not be put to a vote on Wednesday, to keep it live if the IOC doesn't probe Mr Redlich's letter and other related issues.
She accused the Andrews government of backflipping after voting down a push for the IOC to have a non-government chair during the last sitting week.
"This government will stop at nothing to cover up corruption in this state. This deal shows that," Ms Crozier said.
Attorney-General and government upper house leader Jaclyn Symes said Labor "read the tea leaves", as the proposed select committee was likely to recommend a non-government majority and chair.
A previous iteration of the IOC from 2014 to 2018 did not have a chair from the Andrews government.
Ms Symes said she was not afraid of Mr Redlich, whose five-year term as IBAC commissioner ended late last year, if he was appear before the IOC to probe his allegations.
Premier Daniel Andrews, who is still yet to read Mr Redlich's letter, labelled the coalition motion a stunt and said it would have created a "lawyers picnic" over the legality of one committee investigating another.