Matthew Norman: How about a supertax on Blair?

The ex-PM mirrors the bankers in seeming to be rewarded for poor judgement.

For reasons beyond my understanding, the Chancellor has asked me to Christmas drinks this evening at the Treasury in Horse Guards Road. It isn't the most personal invitiation ever, frankly, what with the line beneath "requests the pleasure of the company of..." left blank for the recipient to fill in. But I gather Alistair Darling has been tied up lately with other matters, so we'll let the etiquette lapse pass this once.

The frustration for me is that the party wasn't held a week ago, because I had an idea for Alistair's pre-Budget report.... one I'll trot out anyway on the off chance that he has time for some more populist measures before the election: introduce a one-off supertax on Mr Tony Blair.

That would be the easy bit. The challenge would be working out how much money Mr Tony has, where it is, and what portion of it, if any, is liable to tax. So opaque are his personal finances that a paper has launched a readers' competition to unravel them... a tougher one to win, you imagine, than the fabled Daily Mirror contest that cleaved to Spot The Ball convention in every respect but one (no ball).

For doubtless honourable reasons unconnected with the perfectly legal reduction of tax liability, Mr T has spun a beguiling web of financial structures, involving a dozen legal entities, to handle the £15m, £20m or whatever trousered from his various enterprises since leaving office. Nothing wrong with that. Which of us begrudges him compensation for what he might have earned as an employment barrister had he not sacrificed his best years to serving us so well?

Yet however reassuring it is that he's pocketing £2m per annum for advising the investment bank JP Morgan, and so on, one revenue stream more than ever causes unease. With these newly emboldened chaps telling Sir John Chilcott's enquiry how Mr Tony came to invade Iraq on behalf of us all, you do wonder about the millions picked up from speeches to his American fan base. Isn't this money a highly dubious bonus itself?

This income, predicated purely on his status as America's heroic war compadre, mirrors the banking bonuses in striking the naked eye as lavish reward for what might charitably be called poor judgment. Just as banking houses chose to ignore warnings of impending catastrophe, so Mr Blair ignored Sir John Scarlett's memos cautioning him that Saddam's WMD stockpile was so sub-prime that it couldn't take out (I paraphrase a little) a Basran wasps' nest.

It pains me to propose the Blair Supertax, having said all that, because I'm worried sick how Cherie would take it. As it happens, I saw her a few weeks ago at a charity gala for the magnificent youth theatre company Chickenshed (of which, I should say, I'm a patron), and she looked great. In the roseate glow of the Royal Albert Hall she passed for a decade younger than her 55 years (mind you, I'd had a few that night), and even left the building without the microphones, speakers and musical instruments that she might well have tucked into that legendarily capacious handbag on the assumption that they were freebies.

In the era when you struggled to choose her stock epithet from those bitter rivals "one-woman plague of locusts" and "character from Greek myth... half-woman, half-supermarket trolley", she'd have presumed the chandeliers and half the stage were meant for her. So significant personal growth there, and well done Cherie on that!

It has since become evident, however, that she was bravely masking a familiar agony. "I'll probably never ever stop worrying that I've got enough," she recently told the house journal of the Bennite political wing from which she sprung, Tatler. At much the same time, by way of underlining the neurosis, she was spotted buying gear for their newly acquired Buckinghamshire stately (John Gielgud's old gaff) at the furniture bargain basement known as Christie's. "We're all shaped by our background," Cherie went on. "Not having a pauper's funeral was my grandmother's utter obsession."

If a pauper's funeral begins to look like paranoia, what seems a little less unlikely with each fresh stiletto thrust from vengeful mandarins and spookmeisters (though still a very long shot) is that her old man may yet face a more searching enquiry than Chilcott's, on which Mr T is scheduled to unload his full arsenal of Clintonian legalese in the New Year. But even that would have its compensations.

"Where Tony goes, I go," she tells the Sunday Times. If they do his 'n' her accommodation at The Hague, and let inmates bedeck it with Louis Quinze ormolu tables and Chippendale dressers, their living expenses would be slashed.

In the meantime, this adorable couple plough courageously on, he carving precious moments from sprinkling peace over the Middle East to flog photos at £140 a shot to the premium-rate after-dinner speechgoers of the US; she nipping down the road from their stately to have dinner at Lord Rothschild's even more stately house, where he was hosting a shooting party that included Gaddafi's son and Lord Mandelson (although her visit and theirs did not overlap).

It's an enchanting vignette of the international private jet set back in the early millennial era that now feels so distant to some, and if the Blairs can still join his fellow bankers in guiltlessly enjoying a mildly anachronistic lifestyle, it would be too churlish to resent them for that.

Even so, as we start poring over the newly published MPs' expenses claims (or those not redacted to hell), perhaps it's worth recalling from where this culture of political avarice sprung, and which two beauties were its patron saints.

A supertax is a clunking instrument, and ill-suited to the man of God who sent British troops to Iraq and will reap the monetary harvest for years to come. Much more elegant, surely, were Mr Tony to silence the whispers about his complex financial arrangements, and the fortunes they absolutely aren't designed to spare from tax, with a grand voluntary gesture. A one-off payment to the Treasury of £10m, drawn on the joint account, would more than cover the bill for tonight's drinks. Could anything make the national heart swell with pride like a Christmas gift to an impoverished country from Mr and Mrs Tony Blair?