Tony Abbott could be forced to look again at the broken system of MPs' entitlements, with the Government's powerful audit office poised to probe politicians' perks.
The review could go ahead despite the Prime Minister signalling repeatedly he doubts the system could be improved.
In a proposed work program published this year, the Australian National Audit Office said it could look into MPs' travel entitlements and recent changes to MP entitlements. The probe is on a long list of "suggested audits" submitted to a parliamentary committee in March - well before the most recent furore about politicians' rorts erupted.
Though the Auditor-General has the power to undertake the audit without approval from the Government, Parliament's joint committee of public accounts could order it be given priority.
With the coalition and Labor making it clear they have no interest in dwelling on the expenses furore, MPs could use the committee to delay the investigation.
WA Liberal MP Don Randall was forced to repay more than $5000 to the Commonwealth this month after he used taxpayer funds to fly to the Queensland holiday city of Cairns where he had an investment property.
In an interview with _The West Australian _last week, Mr Randall broke his silence about the affair to insist he did nothing wrong and suggested other MPs had sympathised privately with him because the case took heat off their own conduct.
Mr Abbott has said he is not opposed to changing the system of MP entitlements, but that he has not seen any proposals that would improve the regime.
Opposition Leader Bill Shorten has said he is open to change, but is waiting for Mr Abbott to put forward a proposal.
The Prime Minister has come under fire for his use of travel entitlements to fly to Port Macquarie in 2011 to compete in an ironman event.
Mr Abbott defended the trip, saying he also attended to electorate business while there.
But it was revealed last week the other major event he took part in while in the NSW coastal city was a party political fundraiser - an event for which he was technically not able to claim expenses.