The occasion was the 1982 Budget speech, in which he warned Britain's top bankers that rough treatment of their lovely loot was still very much at the top of the Treasury agenda.
Acres of print has been devoted to Labour's plans for a windfall tax on utility profits. In 1981, though, the Tories had just clobbered the banks for pounds 315m via a special levy on spiralling profits. Hardly in the same league as Labour's will-it-be-pounds 2bn, will-it-be-pounds 4bn, who-knows-how- much utilities tax, but a penal windfall levy from a Conservative government none the less.
And clobber them again it did in 1984, for much more, by abolishing capital allowances that let banks shelter profits behind the booming industry in huge equipment leasing deals done primarily for lucrative tax allowances.
Last week, Britain's top banks emerged from the twice yearly reporting ritual in ruder health than ever before. Profits from the country's top five reached pounds 6.2bn in the first half of the year, with more than pounds 12bn on the cards for 1996 and perhaps pounds 14bn for next year.
Real returns on equity have reached historic levels - more than 30 per cent in the case of Lloyds - against sector highs of around 22 per cent in the1970s and1980s. Rising income and margins, falling bad debts and aggressive cost-cutting have also left dividends surging forwards.
And to rub salt in the wounds, Barclays and NatWest have just given a bumper pounds 920m back to lucky shareholders, making nearly pounds 1.5bn in the last year, as they throw off cash by the bundle.
True, that may be more disciplined than than splurging the money on ill- judged Third World lending or the property bubble, as before. But personal customers and small businesses still reckon they are getting a raw deal in the low-inflation, supposedly low-interest rate 1990s.
There is no suggestion that Kenneth Clarke has even considered a Sir Geoffrey levy. But with the Treasury bare, election tax cuts beckoning and the Government needing a populist boost, market speculation is returning that the banks may just be looking too cushy for their own good.
Consider the five charges for the prosecution:
o Barclays: profits up 15 per cent to pounds 1.3bn; dividends up 15 per cent; and a special share buyback of pounds 470m.
o NatWest: underlying profits pounds 879m, up 23 per cent; dividends up 14 per cent; share buyback pounds 450m.
o Lloyd's TSB: a 12 per cent profits rise to pounds 1.14bn; dividends up 15 per cent; possible buybacks on the way.
o HSBC (including Midland): profits up a third to a staggering pounds 2.32bn; and a 62 per cent dividend hike.
o Abbey National: profits up 16 per cent to pounds 558m; dividends up 20 per cent.
Now for the defence. In the early 1980s, banks argued that profits needed to be high in inflationary times to maintain a strong capital base. Also, they had to store up surpluses for bad times ahead. But with the inflation outlook low and banks voluntarily parting with cash, neither case holds water now.
That old bogey of increased competition ahead is also not much in evidence, with margins increasing, mergers all the rage and the high street leaders behaving like the cosy oligopoly of old.
So what about the final consideration in any arraignment: the public interest and chances of a successful prosecution? Banks might be able to dodge a levy by accounting tricks, lifting bad debt provisions and the like. Retrospective, one-off windfall taxes like Sir Geoffrey's in 1981 are not so easily avoided. The threat of them could be a stick with which to beat charges down.
For many in the markets, the final objection comes down to a gut feeling that it is unfair to single out specific sectors for punitive measures. But, again, there is a strong argument that the banks, like utilities, have imposed a selective tax through increased charges - on all but large corporates - to make good their own past squander.
There is no evidence,either, that Gordon Brown has weighed the pros and cons. Unlike the utilities, the public outcry against banks has largely quietened. Another tax would hark back to a darker, dinosaur past and raise the hackles of a City that Labour has been eager to court. It would also bring intriguing conflict with the unions, who voted resolutely against the levy back in 1981.
With the coffers bare and lots of spending priorities to juggle, however, it could be a card for Mr Brown to keep up his sleeve. He could certainly point to Tory precedent, especially if Mr Clarke deals the populist ace first.
It HAS been a busy week, thankfully in dull August, for the boys (and girls) in blue suits at the Serious Fraud Office.
There were raids on Wednesday morning on the homes of Ashley Levett and Charles Vincent, "Mr Copperfingers" himself, as part of the inquiry into the pounds 1.2bn copper trading losses made by Sumitomo and rogue trader Yasuo Hamanaka. Followed by search warrants on Stephen Hinchliffe and Christopher Harrison in the Facia affair.
In a barely noticed move on Wednesday former City trader Terry Ramsden was indicted on nine charges of allegedly failing to disclose assets to the Official Receiver. He was released on bail and will appear in court in December.
We report opposite on the latest moves in the Hinchliffe saga. On Tuesday receivers KPMG and Grant Thornton, which have done a good job in realising assets, will give creditors the next clue as to the extent of their grief. As for the SFO involvement, more developments are keenly expected.
So Somerfield has finally got its troublesome flotation away. After cutting the offer price twice, and last-minute sale attempts by advisers Kleinwort Benson, the shares closed at 159p, a 14p gain, on their Friday debut.
After driving the price down, City institutions seem to have had it both ways: juicy underwriting and a hefty premium on the shares that is likely to go further. Sounds like a few privatisations we could name.