Autumn Statement: Bankers hit by third levy increase
The scale of the downward revisions to Britain's growth prospects and of upward revisions to government deficit forecasts are plainly going to overshadow everything else that emanates from today's Autumn Statement.
But in the course of the day, as you peer through the economic gloom, you may be able to make out some luminescent red ovals - which will be the faces of British bankers incandescent with fury.
Because for the third time within a year, the government is increasing its levy on banks (in February, it scrapped a lower phase-in rate; and in the March Budget, it increased the standard rate).
Today's latest rise in the levy is designed to protect government revenues: what's happened since the Budget is that the chancellor has found out that his officials miscalculated how much would be raised from overseas banks based in London.
The levy is 0.078% on what banks borrow. And it turns out that overseas banks borrow less in the UK than the Treasury and HM Revenue and Customs thought.
It is possible that these overseas banks have shifted their liabilities overseas, to avoid the tax - though officials don't think that's what happened. They fear they just misunderstood the structure of the banking market.
Anyway, the point is that the Treasury was counting on raising around £2.6bn every year from the levy. And it is now clear that a rate of 0.078% won't achieve that.
So the rate has to be raised.
You might argue that if banks as a group aren't actually paying any more tax, and only the rate has changed, they shouldn't complain. After all, many of you think that £2.6bn a year is trivial recompense to taxpayers for all the mess bankers' reckless lending has wreaked on our economy and growth prospects.
But, whether we like it or not, our economic recovery depends on bankers oiling the wheels of capitalism by providing credit to productive enterprises and deserving households. And that requires the banks to be confident and efficient.
Bankers would say it is much harder for them to set their budgets and plan where to invest in a rational way if the tax rate keeps changing every few months.
More pertinently, an increase in the tax rate will hit the big British banks hardest, because - unlike their overseas rivals - the levy applies to all their borrowings, on a worldwide basis, not just their UK borrowings.
Which means their levy payments will rise both in absolute and relative terms: the burden on British banks will increase.
Hard cheese, you might say. And it seems to be what the chancellor is saying.
Certainly in the case of the semi-nationalised banks, Lloyds and Royal Bank of Scotland, they'll have to pay the extra tax and lump it.
But, in theory, Barclays, Standard Chartered and HSBC have the option of paying a lower amount by moving their respective domiciles, their homes, offshore (to be clear, they'd still have to pay a fair whack, because they would still have taxable debt in the UK).
The Treasury's calculated gamble is that none of them will do this. And there is good reason to believe the Treasury is right, in the case of Barclays and HSBC. Because both could only move if they were able to identify a new national base with all of the following characteristics:
1) It would have to be a big economy, with a central bank whose financial resources were sufficiently large to bail out these huge banks in a crisis;
2) The relevant government in the new home would have to be stable and democratic;
3) The burden of regulation and tax would have to be less than in the UK;
4) The precise choice of new home would not massively annoy customers or government in a different part of the world that is vital to said bank's interests (for example, choosing the US would not go down well in China).
Now when you look at the alternatives available to Barclays and HSBC - China, Hong Kong, Singapore, the US, the eurozone, Switzerland, parts of the Middle East - they fail some or all of the four tests.
So the Treasury may be right that Barclays and HSBC may grump, but they'll have to swallow the bitter levy pill and like it.
The calculation isn't quite the same for Standard Chartered, partly because it is smaller than the others, and partly because it is an overseas bank which by accident of history happens to be headquartered here.
Also Standard Chartered may not have quite the same discretion over where it chooses to call home - in the sense that its largest shareholder, Temasek, Singapore's sovereign wealth fund, could simply decide to buy the whole of the bank (or majority control) and move the HQ to Singapore.
Were that to happen, or were Standard Chartered to choose to emigrate of its own free will, that would be a mild embarrassment for the reputation of the City of London, but not devastating for the British economy.