On Friday morning Premier Daniel Andrews appeared to be standing by Mr Languiller, suggesting he was technically "entitled" to claim the $37,678 taxpayer-funded perk to live in Queenscliff while representing a western suburbs electorate.

Facing growing pressure to dramatically overhaul Victoria's out-dated system of parliamentary entitlements, the premier conceded the allowance was designed for regional MPs forced to maintain a second residence in the city, not the reverse.

"I think it is self-evident that it is an allowance for regional members," Mr Andrews said. "It's an allowance for regional members and he (Mr Languiller) has made it very clear it doesn't meet community expectations."

Mr Languiller's future as speaker now hinges on the critical question of whether he genuinely resided in Queenscliff.

To this end, his vehicle log books will be forensically examined as part of a probe overseen by Parliament's Audit Committee,  led by upper house president Bruce Atkinson.

By 4pm, a formal request had not yet been given to the Audit Committee to commence an inquiry. However Mr Atkinson said he expected to start examining the matter early next week. Financial experts and auditors will also be brought in.

"I want to address the issue expediently in the interest of the parliament, the committee and indeed the speaker," Mr Atkinson said.

"It will be a process that will be independent and will involve some of the external and expert advisers on the audit committee. It will be taking into account both information to be provided by the Speaker, and also seek to understand the Premier's intention to receive recommendations on the entitlements."

Opposition leader Matthew Guy, above, on Friday also dramatically ramped up his rhetoric, warning that Mr Languiller's position as speaker was "pretty close to untenable".

"It beggars belief that Daniel Andrews will not tighten these rules, will not change anything," he said. "The buck stops with him, he is the premier, he leads the Labor party, his members have been caught out rorting, it is time for Daniel Andrews to change the system and to demand transparency from his speaker.

Mr Guy said he was giving Mr Languiller a week to produce documents to prove he was living in a Queenscliff, warning if he did not the lower house would face chaos and the opposition would withdraw confidence in the speaker.

"I don't think they (Labor) can afford another fight, in this case, a damaging row over travel entitlements," Mr Guy said. "I want to see the documentation ... or the house will descend into chaos."

The Coalition said the onus was on the Premier, who had made strong comments on parliamentary standards in opposition, to make sure the speaker complied.