The time has come for Bill "Double Dipton" English to end the charade.
It has been apparent for a while that it is no longer tenable for him to stipulate his primary place of residence as being in his Clutha-Southland electorate when his real home has long been in Wellington.
It is not just a matter of putting things right to satisfy the Cabinet Manual's requirement that ministers "behave in a way that upholds, and is seen to uphold, the highest ethical standards".
His highly questionable claim to be an out-of-Wellington MP - a status which made him eligible for an accommodation allowance while in Opposition and which entitles him to taxpayer-funded ministerial accommodation now he is in Government - has become unsustainable in purely political terms.
Yesterday's announcement by the Office of the Auditor-general that it is making preliminary inquiries before determining whether to investigate whether Mr English has satisfied the criteria of being an out-of-Wellington MP ups the ante considerably.
The possibility of the watchdog of public spending investigating the Minister of Finance does not bear thinking about - at least from National's point of view.
Mr English needs to forestall any investigation by removing the grounds for it taking place.
Mr English's inclination will be to tough things out.
But the negative publicity over his arrangement with ministerial services, which sees him continuing to live in the Wellington family home while the family trust in which he suddenly no longer has a pecuniary interest gets a nice little earner to the tune of several hundred dollars a week, has not only stained his reputation.
It is starting to blight his ability to function effectively both as a senior National MP and Minister of Finance, while becoming a drag on National's performance in Parliament.
Whether the Office of the Auditor-general - which intervened after a request from Jim Anderton - goes to the next stage remains to be seen.
But even the possibility of an investigation is a victory for the Opposition and an embarrassment for Mr English and National.
Mr English must cut his losses.
He should forego what he sees as his right to an accommodation allowance.
Doing so would recover some of the moral authority he has lost and which he needs to function effectively in the finance portfolio.
There is still time. But not much.
Mr English may be worried he would be making himself liable to pay back all the accommodation allowances he has received since he shifted to Wellington a decade or more ago.
He should not feel he would be under such an obligation.
He should simply say he now realises he made a mistake.
Mr English's predicament has in part come about because of the public expectation MPs should reside in their electorates.
That many don't, will come as a shock to many people.
Those who don't live in their electorates thus feel they have to perpetuate a fiction that they do, especially in large rural seats like Mr English's which feel isolated from and neglected by Wellington.
The publicity of recent weeks has shattered that pretence.
Everyone now knows Mr English lives in Wellington - including ministerial services, which has been so accommodating towards him.
The unit's officials and their minister, John Key, must ask themselves whether Mr English's claim to accommodation assistance he would not get as a Wellingtonian stands up any longer.
Mr English would have done himself a power of good had he relinquished the allowance completely when the Prime Minister unveiled the new rules which will see ministers bulk-funded up to $37,000 a year on the understanding they find and pay for their Wellington accommodation.
Foregoing the money completely would have removed suggestions he was being hypocritical in demanding sacrifice during the recession, while rendering Labour's questioning of his past arrangements with ministerial services as purely academic.
Instead, Mr English obviously felt he had made enough of a sacrifice by paying back the thousands of dollars he had claimed over and above the $24,000 limit in accommodation allowances paid to ordinary MPs.
He had to be dragged kicking and screaming to do even that.
But it has not stopped questioning of his eligibility for an out-of-town allowance, or the deal which sees him continuing to live in his own home on the back of the taxpayer.
Mr English himself has handled all this in woeful fashion, especially when measured against his performance as Finance Minister, where he has been tested by a severe recession, delivered a successful Budget, and driven much of the Government's reform agenda behind the scenes.
In a Beehive where the Prime Minister has put the onus on shutting down problems as quickly as possible, Mr English's housing saga has been allowed to run for the best part of two months.
When it comes to his perks and entitlements as a minister, Mr English seems to have a blind spot.
His normally acute political antennae have gone on the blink.
Maybe he felt his status as Deputy Prime Minister gave him the right to claim the maximum - and more.
Maybe he thought no-one would discover that ministerial services had willingly adapted the rules to fit his family circumstances.
Maybe it was the intoxication of power which made him feel bulletproof.
Mr English's folly is still well short of developing into the kind of crisis for the Government of the likes of those surrounding David Benson-Pope and John Tamihere during Labour's tenure.
However, Mr English's senior position in the National Party hierarchy and his being Finance Minister means the political stakes are considerably higher in his case.
Labour knows from bitter experience of the Benson-Pope and Tamihere exits from Cabinet just how such self-inflicted damage can be distracting and morale-depleting.
It is making life particularly unpleasant for Mr English in Parliament, where he is subjected to a barrage of insults every time he speaks.
He looks visibly shaken by the experience.
Labour has also targeted Mr English's arrangement with ministerial services.
It is applying the scalpel with Pete Hodgson asking detailed questions in Parliament to try to uncover whether there was anything shonky about the deal.
Mr Hodgson is following the same forensic approach Lockwood Smith used in Parliament to embarrass Labour over Philip Field and what ministers knew of the problems surrounding Mary-Anne Thompson's tenure as head of the Labour Department's immigration division.
If Mr Hodgson does not find anything amiss, no matter. If he does, all well and good.
Labour has learnt, however, not to talk up expectations. It is also keeping Phil Goff well away from this one.
Meanwhile, the blot on Mr English's record has altered the dynamics of power in the National caucus.
Mr Key's clout just keeps getting stronger, this week on the back of his successful trip to the United Nations.
Mr English's authority has been weakened, though not necessarily by much.
He remains an essential and formidable component of this Government.
However, regardless of what happens from hereon, the balance of power in the caucus has tilted even more in Mr Key's direction.
- John Armstrong is The New Zealand Herald's political correspondent.
