The conviction of former parliamentary speaker Peter Slipper on Monday and a string of MP travel and expense rorts exposed in recent times mean it is unlikely Australian voters will buy back into this belief any time soon.

Former prime ministers Robert Menzies and John Curtin, while representing opposite sides of the political fence, were both famous for a frugality and scrupulous honesty with public funds that now appear inconceivable. It is doubtful that Mr Curtin, for example, made much use of the war-time equivalent of ''Comcars''. He usually walked home to The Lodge from official engagements in Canberra. Mr Menzies, according to many sources, was parsimonious with public funds and generous with his own. He often embarrassed treasury officials by returning to them the unspent balance of his travel allowance after trips overseas.

Slipper's conviction on dishonesty charges over false statements in travel claims lodged in 2010 is proof things have changed dramatically and not for the better. While some argue he was the victim of a political vendetta because his defection from the Liberal National Party gave Julia Gillard the numbers to shore up her minority government, it is hard to argue with ACT Chief Magistrate Lorraine Walker's ruling on Monday that Slipper's use of the term ''suburbs'' to refer to Murrumbateman wineries on his travel dockets was ''implausible''.

The court heard the three trips included visits to Clonakilla in Murrumbateman, a $25 bottle of sparkling purchased at Gallagher Wines and lunchtime stops at Wily Trout Wines at Poachers Pantry, known for its gourmet smoked meats. Slipper had used his government-issued Cabcharge allowance to pay for the trips on the basis he was on parliamentary business. In handing down her decision, Ms Walker said Slipper was travelling outside his entitlements, and knew he was doing so.

Having been found to have deliberately provided misleading information over $1000 worth of vouchers, Slipper must now pay the price. He will be sentenced on September 22 and could be jailed for up to five years. The former speaker's substantial retirement benefits after 23 years in parliament are also at risk.

Will the scrutiny of Mr Slipper's travel rorting lead to any meaningful change in the way politicians treat public money? The "age of entitlement" may be over, according to Treasurer Joe Hockey, but the latest Department of Finance records show politicians continue to spend tens of thousands of taxpayer dollars on flights to sporting events, study tours, recipe collections and even children's books.

Times, and the rules governing parliamentary perks, have certainly changed since his day, but when Mr Menzies was an honourable member he was known to only claim against an item or event if it was entirely for official business. If it was a mix of business and pleasure, such as a dinner during an international visit attended by friends as well as associates, he would cover the cost.

Mr Curtin, never a fan of air travel, journeyed thousands of kilometres on red rattlers and spent hundreds of nights in budget country hotels. He might therefore have had a few terse words to say on the floor of the House if it had been put to him that attending weddings constituted parliamentary business for an MP when it came time to lodge expenses paperwork.

Last year, following a wave of criticism over politicians' expense claims, Prime Minister Tony Abbott repaid more than $11,000 in entitlements, including a travel allowance to attend the weddings of then colleagues Slipper and Sophie Mirabella. Coalition frontbenchers George Brandis and Barnaby Joyce repaid $2200 claimed after attending the wedding of former 2UE shock jock Michael Smith.

The fact is our MPs enjoy thousands of dollars in entitlements above their $200,000-plus salaries. Under the present honour system, taxpayers rarely know when extra expenses are misclaimed or whether they have been repaid. Unfortunately, the details of the Slipper case, on top of lingering cynicism over how MPs' entitlements are administered, will have most taxpayers feeling decidedly short-changed despite the guilty finding.