The Inland Revenue received an anxious enquiry from a British stockbroker with a plummy accent last autumn. What would be the financial implications for him of his plan to retire the very next day and sell his shareholding in the firm?
He was having cold feet, because a colleague had told him that the 'socialist' chancellor of the exchequer had reformed capital gains tax in a way that would make him millions of pounds richer if he deferred his retirement for a year or two.
This seemed counter-intuitive. Could it really be true? The broker asked an amused revenue official whether Gordon Brown, the scourge of so-called fat cats in opposition, really wished to enrich folk like himself, who - to be candid - are not short of a bob or two.
The answer from the revenue was an unqualified yes. Since 1997, Labour has progressively reduced the burden of capital gains tax on so-called 'business assets', which include the shares held by employees in their own companies.
The latest phase of this reform, announced in June as the Government's first major initiative after the Tory rout of June 7, is the most generous of all. As of next April, if the assets are held for just a year, CGT falls from 40% (for higher-rate tax payers) to just 20%. And held for just one more year, the rate falls to 10%.
This tapering system will replace Brown's earlier reconstruction of the tax, which reduced the rate to 10% if assets were held for four years.
And it contrasts sharply with the system under the previous Tory government, which levied a full 40% rate.
The point of the reform for Brown is to encourage individuals to take risks by creating or developing their own businesses. It is part of his package designed to promote entrepreneurialism.
However, the reform does not discriminate between new companies and very old ones. Nor does it make a distinction between industries where the UK already has a competitive edge, such as financial services and media, and others - such as hi-tech manufacturing - where a bit of fiscal stimulation might be useful.
Now one business that has been doing very nicely for 177 years without G Brown's help is that most pukka of British stockbrokers, Cazenove and Co. But as it prepares to be floated on the stock exchange next year, its 122 partners have reason to be extremely grateful to the chancellor.
As a quoted company, Caz's value is likely to be somewhere between pounds 1 billion and pounds 2 billion. On the fairly conservative assumption that listing the shares creates a capital gain for the former partners of more than pounds 500 million in total, then Brown's CGT change could cost the Treasury more than pounds 150 million on this one deal alone.
On a smaller scale, the successful young public relations firm Finsbury has recently been bought for cash for around pounds 50 million in staggered payments by WPP, the advertising giant. It was created only six years ago and thrived when the CGT regime was very different. But its senior executives are many millions of pounds wealthier, thanks to Brown.
Similarly, of course, the chancellor cannot restrict the tax advantage to employees of UK-owned firms. All that matters is that the individual pays tax in the UK. Thus, the senior UK-based managing directors of the US investment bank Goldman Sachs - each with shares worth many tens of millions of pounds - benefit from Brown's largesse. And there will be a similar gain for British domiciled consultants of Accenture, the former Andersen Consulting, when it floats on the New York Stock Exchange this summer.
This is a corking tale for the tabloids. Brown has in effect transferred a substantial chunk of public-sector revenue to a limited number of already wealthy individuals in the City. The price of fishing rights and shooting rights will be bid up as hospitals, trains and schools plead for additional cash.
The Labour left will be outraged when it cottons on to what has happened.
It was one thing for New Labour to reject redistribution from haves to have-nots, but giving tax handouts to the haves? That is socialism stood on its head.
However, the tax change can be robustly defended as a measure pour encourager les autres. But one aspect of the reform does seem disproportionately generous, as my friend the broker discovered when he rang the Revenue. When mulling whether to retire and give up his CGT windfall, he asked what constituted employment for tax purposes. If he worked a day a week, would he still be deemed to be employed by his firm? Yes, said the Revenue official, because it is illegal under European Union rules for the Government to discriminate against part-time workers. How about half a day a week? No problem. Just an hour a week? Yup, said the Revenue.
As you can imagine, this version of the New Labour meritocracy has won a convert. As he bathes in Krug, he will be saying a very special prayer for Gordon Brown