Timing is everything. It is the failure of some 200,000 people to pay their tax bills on time, coupled with the fact they ignored subsequent warnings to cough up, that has caused HM Revenue and Customs (HMRC) to propose that money owed should be seized from the bank accounts of the wantonly tardy without a court order. Given that filling in a tax form is on a par with going to the dentist for a tooth extraction in the popularity stakes, the proposal has inevitably been greeted with anger and disgust.

Timing is everything. It is the failure of some 200,000 people to pay their tax bills on time, coupled with the fact they ignored subsequent warnings to cough up, that has caused HM Revenue and Customs (HMRC) to propose that money owed should be seized from the bank accounts of the wantonly tardy without a court order. Given that filling in a tax form is on a par with going to the dentist for a tooth extraction in the popularity stakes, the proposal has inevitably been greeted with anger and disgust.

There is an important issue to address concerning individuals and companies going to the limit and beyond to avoid paying tax. Pursuing them is a costly and time-consuming business. When the courts are involved, defaulters can exploit another opportunity to put their assets beyond the taxman's reach.

Devious methods might, in certain circumstances, demand a desperate response, HMRC suggests. Unfortunately, it has found itself not only on the back foot but facing an onslaught of killer bouncers in the PR game to win hearts and minds.

Only hours after news of the proposal emerged yesterday, the National Audit Office published a report to show that, in the financial year recently ended, more than one million people had paid the wrong tax because of errors by HMRC.

Yes, timing is everything. The watchdog said some £157m in tax was overpaid, while underpayments accounted for some £125m. The effect might be broadly neutral in the Treasury scheme of things, where officials and ministers are accustomed to dealing with digits with nine or 10 zeros behind them. But each person who pays too much tax is the victim of a system with a record of efficiency that falls short of expectations. They are out of pocket when they should not be, and can be put under stress to reclaim what is theirs.

The report found that pensioners were among those people most likely to be victims of processing errors. The vulnerable should be among the most protected in the system, not the most exposed to its failings.

Clearly, there is work to do to put matters right, and HMRC must undertake it as a matter of urgency. In the context of yesterday's controversial proposal, it says there would be safeguards to ensure that only people and businesses it pursued for non-payment of tax would be subject, as a last resort, to the sanction of bank accounts being frozen and sums owed to government being removed.

It is a difficult enough argument to make - and guarantee to give - at the best of times. When HMRC is shown to be at fault in the business of collecting the correct amount of money from people who are willing to meet their tax obligations, the task seems daunting. HMRC needs to put its own house fully in order before the debate can legitimately be had on how best to clamp down on persistent tax-dodgers.