Current Treasurer Joe Hockey and former Liberal Treasurer Peter Costello both criticised Mrs Bishop's use of expenses on Sunday, with Mr Hockey pointedly noting that he hadn't "heard of anyone who has taken a helicopter to a fundraising event". Defiant: Bronwyn Bishop attends a memorial service at the Sydney War Memorial on Sunday to commemorate the Battle of Fromelles. Credit:Steven Siewert The Department of Finance is now conducting an audit of Mrs Bishop's expenses, despite Labor writing to the Australian Federal Police and requesting an investigation, as happened with former Speaker Peter Slipper. But in comments that ratchet up political pressure on the Prime Minister for the mistakes of the Speaker, Mr Shorten said on Sunday that Mr Abbott needed to act and remove his "captain's pick", Mrs Bishop, from the Speaker's chair. "This has now become a test of Tony Abbott's leadership. Does Mr Abbott have the character to tell Bronwyn Bishop to stand aside? Because he knows - and the world knows - that this arrogant misuse of taxpayer funds needs to be held to account," he said.

"He can't dismiss this, as he apparently has, as village gossip ... Mr Abbott's Liberals are addicted to privilege. Expenses: Bronwyn Bishop at Saturday's press conference. Credit:James Brickwood "There is not a hint of apology in the ranks of the Liberal Party, there is no apology from Mrs Bishop, she just doesn't seem to understand what the fuss is about." Earlier on Sunday, Mrs Bishop was swamped by journalists after the unveiling of a new Anzac memorial in Sydney's Hyde Park. She faced further questions about the $5000 charter helicopter flight from Melbourne to Geelong – a journey that takes as little as an hour by car - and dismissed suggestions she should apologise.

"When we talked about the helicopter, that is now with the Department of Finance so I don't think it's appropriate to talk about it any further, except to say, if you look at other people's charter allowances, I think Mr [Tony] Burke spent in the same period $31,000. You have got to get things into proportion," she said. "The best form of apology is to repay the money." A journalist countered: "The best form of apology, Mrs Bishop, is to say 'I'm sorry.' " But she swatted away that question and claims her case was comparable to that of Mr Slipper, who faced public wrath over his use of Cabcharge dockets, describing it as "totally a different matter altogether". And Mrs Bishop also attempted to justify the huge expenditure involved in a recent two-week trip to Europe.

"It wasn't $90,000, it was $88,000," she said of Fairfax's recent coverage of her fortnight-long trip to Europe, including time spent campaigning for an international job. And she repeated her claim that the money on the helicopter flight was spent within the rules, which requires expenditure to relate to the duties of office, even though she was attending a party political fundraiser. The event was, in fact, a form of community outreach, she said. Loading "The [criticism about the] grandiosity [of arriving in a helicopter] is quite right," she said.

"That's why I've repaid the money."