MPs are being paid $1.8 million for work expenses, including entertainment and gifts, but refuse to account for the money.

Not a single New Zealand MP has agreed to disclose what they do with their expenses top-ups, taxi reimbursements and accommodation allowance, despite a dozen of their British counterparts losing their jobs over similar issues.

Stan Rodger, the former Labour MP who chaired a 1999 review of Parliamentary services, is calling for greater transparency around MPs' expenses.

Parliament's refusal to disclose its affairs through the Official Information Act was "regrettable", he told the Herald on Sunday.

Taxpayers' money funds the allowance system for New Zealand's 121 MPs, but they are not required to keep any record of what they spend the money on.

Each MP receives $14,800 a year for expenses, except the Speaker, Lockwood Smith, who gets $18,400, and Prime Minister John Key, who gets $19,700.

The money is on top of their salaries, which range from $130,000 for a backbencher to $393,000 for the Prime Minister.

On top of the $1.8m in work expenses, MPs from outside Wellington were entitled to up to $24,000 each to cover Wellington accommodation costs - a sum that could approach $2.5m.

And last year, they claimed another $10.3m in reimbursements for the money they spent on air tickets, taxis, rental cars and driving their own cars.

Parliamentary whips are required to cut off travel privileges to MPs who run up too many expenses, but Labour's Darren Hughes refused to say which, if any, Labour MPs had been so penalised.

National whip Nathan Guy failed even to return calls, simply emailing across a copy of the rules on expenses and allowances.

John Key said this week that there were "quite clear differences" between the British and New Zealand systems, but he acknowledged that the transparency of New Zealand's system was a subject for legitimate debate. He said it should be taken up with the Speaker, Lockwood Smith.

The level of the expense allowance is set by the Remuneration Authority, an independent body whose guidelines say the money is for entertaining staff and constituents, koha, gifts and even luggage.

But, after a revamp of expenses in the wake of public anger at the accommodation claims of ministers Marian Hobbs and Phillida Bunkle, the MPs no longer have to keep any record of what they spend the money on.

And with the Remuneration Authority's expenses determination expiring next month, MPs' allowances could soon be boosted higher.

Stan Rodger's review of the Parliamentary Service Act, in 1999, recommended that MPs' spending be disclosed under the Official Information Act - as ministerial and departmental costs can be disclosed. But the MPs rejected the advice, keeping their spending secret.

"That was regrettable," Rodger said. "It would have been greatly beneficial and accountability would have been enhanced."

Attempts by the Herald on Sunday to discuss allowances with our 121 MPs received a cold shoulder from members.

Not a single member of the House agreed to answer any the questions submitted to them on their expenses and other benefits, including travel and accommodation.

Green Party co-leader Jeanette Fitzsimons and Act leader Rodney Hide - the one-time "perkbuster" - both called for greater transparency.

But neither disclosed how much they had run up on travel, nor disclosed what they'd spent their expenses allowance on. Hide came closest: he said he had once put on drinks for staff, but did not give details.

Parliament's former speaker, Margaret Wilson, said in 2007 that Parliament's exclusion from the Official Information Act was "anomalous".

But Speaker Lockwood Smith said disclosing the information would be "ridiculous".

He described the present system as "very transparent", and said that disclosing expenses information could breach MPs' privacy. "Somewhere a line's got to be drawn."

Smith was quick to distance local MPs from the scandal engulfing the House of Commons in Britain.

"Rest assured our system is totally different from the UK and there are several layers of monitoring to make sure the system is not abused," he said.

Political scientist Dr Joe Atkinson said the refusal by MPs to open the books was "self destructive" and typical of a pattern to "guard private parliamentary privileges very closely indeed".

Atkinson said parliaments tended to act only when there were scandals, and the system needed to change.

"There is a crisis of confidence in politicians and Parliament, there is a deep distrust of the legislative system and the only way they're going to repair that is to be pristine."