The Prime Minister, John Key, says Ministerial Services may get more powers to deal with inappropriate credit card spending.
Official documents released on Thursday show several ministers have used their credit cards for personal purchases over the last decade.
Mr Key says he expects Ministerial Services, which is part of the Department of Internal Affairs, to challenge ministers who spend taxpayers money outside the rules.
He says he would be happy to see details of ministers' credit card spending regularly released to the media.
A spokesperson for Internal Affairs, Allen Walley, says the likelihood that their spending will become public knowledge will bring errant ministers into line.
He says while Ministerial Services could withdraw an offending minister's credit card, the focus has been on ensuring money is reimbursed.
New Zealand First leader and former Foreign Affairs Minister, Winston Peters, says ministers' use of credit cards has to be viewed realistically.
Mr Peters says when he was a minister, there was one credit card, held by a staff member, to pay for the entire official party, otherwise it would have been a logistical nightmare.
He says personal expenditure did sometimes come up on the card, but it was reimbursed.
Mr Peters says it was his understanding the practice was well within the rules.
Shane Jones to face colleagues
Labour MP Shane Jones will plead his case to caucus colleagues next week after admitting he used his ministerial credit card to pay for pornographic films.
Several ministers have been guilty of using their cards to buy personal items, then repaying the money later, contrary to the rules.
Most attention has focussed on the spending of Mr Jones, who has been reprimanded by his leaders and will have to face his fellow MPs on Tuesday.
Mr Jones was a cabinet minister in the last Labour Government.
He says he won't be making any rash decisions about his political future but acknowledges the potential damage the disclosures could cause him, including among his Northland constituents.
His spending was detailed in boxes of documents containing receipts for ministerial credit card spending for the period April 2003 - February 2010.
Another Labour MP, Mita Ririnui, has repaid money spent on a bike, a golf umbrella and purchases at Mitre 10, to name a few.
Former New Zealand First leader Winston Peters made several reimbursements for food, bar tabs, cigarettes, clothing and a sauna.
Trade Minister Tim Groser has incurred bills amounting to almost $500 for mini bar and alcohol purchases during a week in Copenhagen.
Labour skeletons
Prime Minister John Key says the disclosures over ministerial credit card spending show the Labour Party has a few skeletons in its closet from its time in Government.
Mr Key told Morning Report that the episode has not reflected well on politicians generally and could undermine public confidence in MPs.
He said Labour Party leader Phil Goff, who has been highly critical of spending by some National ministers, must take his own MPs to task.
Mr Key said he has made it clear to National MPs that their behaviour must be able to withstand public scrutiny.
He also said the public has to understand that MPs have a very unusual job, involving frequent travel and the costs that go along with that.
Reaction in Northland
Some people in Northland say it does not matter what Mr Jones bought with his ministerial credit card, because he has repaid the money.
Ngapuhi elder Kingi Taurua says he admires the former Labour minister for admitting what he did, but he's shocked Mr Jones spent taxpayer money on booking pornographic films.
A relative, Tame Kahiti Mare, thinks his nephew's spending is not the country's business because he reimbursed the money.
Te Runanga o Ngati Kahu chairperson Margaret Mutu says she's disppointed by Mr Jones' actions, but says it will be up to his party to decide how to deal with them.
Overseas spending defended
Progressive Party leader Jim Anderton has defended temporarily charging some personal spending to taxpayers while on official duties overseas.
Mr Anderton, who was a senior minister for nine years in Helen Clark's Government, says officials dealt with all his bills when he was overseas.
He says he reimbursed Ministerial Services for any personal spending on hotel accounts, such as massages for his bad back, when he returned to New Zealand.
