The Tories said we had published a figure of 200,000 for the likely number of non-doms. Which is true, but we can't claim the credit for it. We were following up a story in The Observer, which said:

The Inland Revenue revealed this year that 112,000 people filled in a 19-question, self-assessed non-dom form for the tax year 2004/05. But it is thought the figure for 2006/07 could be 200,000 or more. (I can't find the link for the exact story at the moment - sorry)

I suppose in some sense our name was being used to add credibility, which is fine by me: quite flattering, really. The Independent rang up yesterday and we were quoted adding that we had simply got the number out of the papers (perhaps I wasn't clear enough when explaining it to The Indie: we thought the number was credible) and that it was probably a 'back-of-the-envelope' calculation.

It's all getting a bit muddled, as far as I can tell. What's the reality of the situation?

Firstly, I would stand by the 200,000 number. We just, disappointingly, didn't get there first (and The Observer deserves credit for having consistently followed the non-dom issue where their rivals haven't).

The number for 2005/6 is 114,000. The suggestion is it has probably gone up since then because of the Offshore Disclosure Scheme, which in targetting several hundred thousand people with offshore tax liabilities must certainly have encouraged a few 'non-doms' out of the woodwork. It would be a neat way of getting out of a tax bill overnight (it might not work, I might add).

Whether I would use 200,000, or even 150,000, as the basis for a calculation of a tax policy on non-doms I don't know. I think it would be a prudent accounting view to use the latest published figure, 114,000, at least.

Of course, even that would have landed the Tories in a row of sorts, because the Treasury then, amazingly, came out and said only 15,000 people would have enough offshore income to make it worth their while to pay this.

I'm not sure that was a terribly sensible thing for the Treasury to do.

It, after all, has no more idea than you or I what non-doms have in their offshore bank accounts. Many of them don't even tell their accountants how many millions there are stashed away. The only question their tax advisers ask them is 'are you a non-dom?' If the answer is yes, that's the end of the conversation.

Besides all of that, is it a good policy? I think it's politically clever but not the right solution objectively. Ultimately, I think the tax exemptions should go. They don't really have any place in a modern tax system and represent a bizarre subsidy to a even more bizarre sub-section of the population (investment bankers and many premiership footballers, among others).

It's politically clever because it could be dynamite in an election campaign.

I re-acquainted myself with Gordon Brown's lines on the subject in 1994 yesterday. He said:

Those who are non-domiciled are able to live in the UK free of tax. It is easy for the well-advised to bring in money from overseas without becoming liabile to tax. In 1988 the Inland Revenue recommended a radical new approach to residence and domicile. The government rejected the proposals. When Labour tried to introduce the proposals in the Finance Bill, the then Financial Secretary Mr Dorrell spoke of 'substantial representations' - presumably from those like Asil Nadir who fund the Tory party and remain outside the tax net.

The shoe is now on the other foot. The Tories want to tax the non-doms, Labour doesn't.

And in an election campaign, if I remember rightly, political parties must disclose donations on a weekly basis. Every week the campaign goes on and this issue is discussed, won't it be difficult for Mr Brown to defend his policy in the light of those whom we expect to fund his bid for power?