John Key's once squeaky-clean image has been blemished by his failure to disclose the full extent of his Tranz Rail shareholding before Labour embarrassed him by doing it for him.
But his reputation is a long way from being irrevocably tarnished by Labour's revelation that he owned 100,000 shares in the rail operator when everyone had been led to believe the figure was closer to 30,000.
Labour has finally landed a big hit - but not the king-hit it has been looking for.
The story, which dates back to 2003, is too old and arcane for most voters to be bothered about.
The only thing that has really changed since July when the Prime Minister first alleged Key had a conflict of interest is that the actual number of Tranz Rail shares he owned back in 2003 has been found to be much higher than thought, thanks to the dogged digging of Labour's taxpayer-funded Parliamentary research unit.
Once again, labour is in danger of over-egging things. the triumphalism Labour MPs displayed yesterday at having skewered Key on the question of whether he can be trusted might have been wonderful for party morale. It also spoke of Labour's relief at finding something substantial to dent the credibility of National's leader, such is Labour's desperation.
It is sometimes better to just let the public make up its mind on the facts rather than constantly blitz voters with your version of what they mean.
But if the television pictures of gloating Labour MPs risk rubbing voters up the wrong way, the images of Key look much worse.
Key has been damaged by being caught out on camera - just as he was this month when he finally, but reluctantly, admitted to TV3 he was the National Party figure who had met Lord Michael Ashcroft during the visit by the wealthy benefactor of Britain's Conservative Party.
On One News on Monday night, Key was once again seen to fudge, then hesitate, then admit and finally apologise for misleading the public.
Such television images are terrible for Key. They are a major worry for National's election strategists as those images will stick in voters' minds long after the ins and outs of the story they are illustrating have been forgotten.
The fact that Key is mucking things up now is not a good prognosis for his avoiding mistakes in the white-hot heat of the formal four-week election campaign where the pressure is such that lapses are easily made.
As Labour's Michael Cullen observed yesterday, Key's demeanour in the One News grab was that of a child whose hand has been caught rifling through the cookie jar.
Key's prime task yesterday was to extract his hand with a modicum of dignity. He succeeded in doing so by confessing to having made mistakes, particularly in failing to reveal he had owned more shares than he had realised in July. Having later found that out from his sharebroker, he accepted he should have said so.
The best thing Key can take from this episode is that it is another wakeup call. Two weeks ago, he was lecturing his MPs about discipline after someone within National left policy documents lying around Parliament. After listening to that, Key's colleagues must have been shaking their heads in bewilderment watching Monday night's news.
The polls still look very good for National. But since the election date
was announced nearly two weeks ago, it has shown all the urgency of a sloth in slow motion.
So far, that has been hidden by the furore surrounding Winston Peters. but it won't be for much longer.