No, Peter, these excuses just won't wash any more

He launched himself on Labour's deputy leadership campaign in pursuit of a higher profile and ended up last in the field, severely out of funds and struggling to explain how more than £100,000 in donations could have gone unreported until long after the race. He also turns out to have been partly funded by a gaudy coalition of interests and an organisation called the Progressive Policies Forum which had no previous existence.

Is it progressive politics to behave like this? Not in my book and not in Mr Hain's, if he had been observing the first rule of self-preservation: think how what you are doing will look if it gets out.

In his News at 10 interview last night, the Prime Minister showed his determination to keep his ailing minister and added that his ordeal was down to "incompetence that he has readily admitted to".

This is inadequate on two fronts. Incompetence is worse than the oversight Mr Hain cites. Added to which, the minister did not "readily" admit the scale of the mess he was in. Indeed many of his colleagues have complained privately that one of the damaging aspects of the affair is that the story has been strung out from a minor admission before Christmas to the present far greater debacle.

If, as one of the PM's key allies, Ed Balls, says, Britain should have "the highest standards in public life", it is not going to get them by turning a blind eye to a major mishandling of funding by a senior Cabinet figure.

There is a view that, outside the Westminster village, none of this really matters. I disagree. If politicians behave by standards entirely different from most other people, they are on the wrong side of the democratic process when they are supposed to be its guardians.

In normal life, subterfuge - even if not illegal - is seen as wrong or untrustworthy. In fundraising, it has too often come to be seen as the norm. That is the crux of the matter, which no amount of weaselling can dispel.

Mr Hain is way beyond any line of acceptability here. It's not something I am predisposed to say, having always found him an engaging and lively figure. Once he gave me an interview in which he let slip that he thought Britain had the "worst trains in Europe". When the row duly erupted, he fought back with some spirit and saw the funny side (eventually).

There are many occasions when simply amassing ministerial scalps seems to me pointless. Alas, this is not one of them.

Whether it was "not wilful" - as he asserts - is beside the point. It was careless to the point of recklessness, a characteristic which has been a hallmark of all the other money scandals besetting the Government from the blind eye to conflict of interest in the cash-forhonours affair, to tolerance of David Abrahams's multiple identities and shabbily run deputy leadership campaigns.

For the PM, attempting a fresh start in 2008, this is agony. "And all for a deputy leadership!" wails an ally. Mr Brown sticks to Mr Hain (who is only a latter-day Brownite) largely because he wishes to avoid a domino effect.

Having backed Harriet Harman, who also sported irregularities in her campaign funding but won the race, that decision is harder to defend if he shoots down Mr Hain.

Still Mr Brown might have been better advised to see this embarrassment for what it is and told his minister to resign once the scale of the imbroglio became clear. For a start, Hain cannot adequately do his job as minister for welfare reform at a crucial point in the battle of ideas with the Opposition.

The Conservatives last week produced a package of attention-grabbing measures on prodding those reluctant to work. Some of the ideas are very well thought through - indeed culled from a radical review which Labour did not fully implement.

Some of them, like all grand schemes borrowed from other countries, are questionable in terms of the money spent, likely outcome, how many people will benefit or suffer and so on. Policies thrust upon us as wondrous cures should be tested in the heat of debate.

Instead, Mr Hain is running in an endless loop on the TV, looking anxious and vexed and defending himself on breaches in rule-keeping (which is not a good idea if it is part of your job to clamp down on those who bend or break the rules of the benefit system).

Nemesis has it that the Conservatives should also come under pressure on the funding of the shadow chancellor's office. This is not accidental: there is cross-party mess and confusion about how donations are supposed to be reported and the willingness of the parties to do so. At least Mr Osborne reported his office donation to one of the relevant authorities. He was not, however, exactly keen to share the information-as widely as possible. So it grates to see David Cameron adopt a holierthanthou tone at a launch entitled "Trust in politics", when his party's own registrations on office donations were incomplete and his main donor and treasurer, Michael Ashcroft, is evasive about whether he is resident in the UK or not.

Transparent is as transparent does. If Messrs Cameron and Osborne want to be seen as truly different, they can't play by the dodgy old rules and hope we will esteem them for it. One senior member of the Cameron team replies: "Well, we never claimed we were outsiders to the political system, tearing everything up." In other words: don't expect us to be, as Mr Blair used to say, "whiter than white".

Oh really? Is the New Conservatism still built on the old nods and winks? I do not think that is what Mr Cameron wants to put across as he lures swing voters as the "change candidate". If he wants to be Barack Obama one week, he can't be the ultimate insider the next.

Let's be clear on this - since few serving politicians are. The reason these situations arise is that the parties do not really want funding to be transparent because they fear there will be less of it.

The defence mooted by Mr Cameron (and not just him) is that he is only required to be honest within the rules. If Mr Brown wanted to show that he was serious about cleaning up politics, he could have sent a warning signal to others by asking Mr Hain to step down. Honesty is not just about the letter of the law or its implementation: it is about a state of mind and a desire to change tired old excuses for hiding things.

Until politicians come to terms with this inconvenient fact, they can ask us to Trust in Politics all they like. And we should promptly tell them why we don't.