Taxpayers have a right to know how their dollars are being spent. That includes the allowances paid to the country's parliamentarians for accommodation or travel, as some MPs have learned to their discomfort over the past year or so. It should also include the use of public money to cover legal costs when parliamentarians are sued. Yet taxpayers are in the dark when it comes to their footing of MPs' legal bills because, unlike Cabinet ministers, MPs are not subject to the Official Information Act. In the interests of transparency, this must change.

Until 2001, there was no provision for taxpayer funding to be used for MPs' legal costs. MPs had to foot their own bills. Since then, they have been allowed reimbursement of expenses to defend legal proceedings taken against them "in his or her capacity as a member of Parliament". Approval of the party leader and the Speaker is required, and the money comes from the party leader's budget - the Parliamentary Service funding for the running of leaders' parliamentary units.

Clearly, there are occasions when it is legitimate for MPs' legal bills to be paid with public money. Parliamentarians should act vigorously on behalf of their constituents. The very status that means they must sacrifice some of their privacy also makes them prone to legal action. National MP Nick Smith is the subject of a defamation case brought by a timber preservative company for comments he made while the Opposition building spokesman. An unknown percentage of his legal costs are being met by the public purse.

Two other MPs received thousands of dollars to defend separate defamation claims by fellow MP Winston Peters, neither of which succeeded. In another case, National MP Gerry Brownlee requested reimbursement of up to $48,000 for a civil assault case taken against him by an environment activist in 1999. This was, rightly, refused, and Mr Brownlee has acknowledged it would not have been an appropriate use of taxpayers' money.

Yet but for the publication of documents by the New Zealand Herald and an admission by Dr Smith of the use of some public funding, taxpayers would have been none the wiser about either of the requests for reimbursement or their granting or denial.

It is a moot point whether a party leader and the Speaker are the most appropriate arbiters of the use of public money for legal costs. This is an area where there will be shades of grey. Certainly, they might be inclined to apply a hotter blowtorch if they knew their decisions would be disclosed publicly. Full transparency would mean there would be an outcry if taxpayers' money was seen to be going to legal proceedings that related to activities outside politicians' work as an MP. MPs would also think longer and harder if they knew their applications for reimbursement would be public knowledge.

The Prime Minister, John Key, said yesterday that taxpayers were entitled to know that money from the public kitty was being used for MPs' legal costs, and that he would be open to such information being made public. That is a refreshing outlook, and one that indicates Mr Key is fully aware of the harsh spotlight on MPs' expenses and allowances, both here and in Britain.

Other MPs, regrettably, have been slower to learn the lesson. A sense of entitlement lingers. Given the chance, some MPs would continue to make light of notions that the public have the right to know what their elected representatives are up to, and how their money is spent. In reality, much has changed since 2001 and parliamentarians must expect to be subjected to far more exposure as an appropriate degree of transparency is established. Disclosure of the use of public money for MPs' legal costs should be another step in that direction.