Elegant bunkum but bunkum nonetheless. First, many of the most dramatic economic effects of EMU - including the locking of interest rates by the participating countries - will probably be apparent well before 2002. Second, if Tory policy is so pragmatic, why on earth was it hardened last year from one of ruling out EMU entry "in the foreseeable future" to one of ruling it out for 10 years, other than to appease those in the party - Howard foremost among them - who are implacably opposed to British entry into a single currency on unchangeably political grounds?
But bunkum for a reason. The alternative defence, that the letter was merely the same old pro-European story from the same old faces was always a bit threadbare. Ask yourself who at the moment has more resonance with the British electorate: Ken Clarke and Michael Heseltine - or the current Shadow Cabinet, William Hague included? But threadbare or not, it wasn't available. For the big new catch in yesterday's list is Chris Patten. The former governor of Hong Kong didn't have to sign the letter. He is busy, 70,000 words into his big book about Asia. He isn't by instinct such a full-blooded enthusiast for EMU as - say - Lord Howe or Ken Clarke. Indeed those who talked to him during John Major's visit to Hong Kong in March 1996 were left with the unmistakable - and rather surprising - impression that he was nearly as sceptical about a single currency as Major himself. And yet he took little persuading to sign up to yesterday's letter. So what's he up to?
The first thing to say is that Patten has become distinctly interested in the domestic scene once again. Expect a series of speeches and articles about some of the big questions in British politics: issues from welfare reform and the terms on which Blair might be able to build a cross-party consensus for it - to local government and how Treasury resistance to giving it more power should be overcome. This doesn't, I think, mean that he has decided what to do when he finishes his book and the accompanying television programmes in the autumn. At one level, something relatively non-political, at least initially, is always possible. Who better for example to front and write a TV mega series on the British Empire? But Patten's career has been all about big public sector jobs; he notably hasn't ruled out going for the London mayoralty. And would he be able to turn down, if and when Leon Brittan stands down, the EU commissionership which Tony Blair would be sorely tempted to offer him? The idea of playing second fiddle in Brussels to Neil Kinnock would certainly not attract. The prospect of a plum EU portfolio just might.
But on the big question of whether to return to mainstream politics, Patten is still keeping his options open. He is unusually hesitant about foisting himself on a suddenly available constituency in a by-election - a course he refused after he lost his seat in 1992. He would surely be uninterested in the prospect of a job, even, if it were ever to arise, the top job, in his party if it looked likely be in semi-permanent opposition. Some well-connected Tories believe that a referendum vote in favour of PR - and the consequently real prospect of a business friendly, pro-European grouping breaking way from the Hague-led Tory party - remains by far the likeliest possibility for luring him back to the Commons. But whatever turn his career takes, he did something important by signing yesterday's letter. Lenin would have called it siding with your "objective allies". But whatever you call it, it clearly tells the beleaguered pro-European left in the party that whatever private doubts he may have had about the single currency he, along with Clarke and Heseltine, is on their side.
For it is precisely Patten's relative agnosticism about EMU entry that makes his signature on yesterday's letter so important. Patten has always been more excited by the widening of the EU than its deepening. He probably wouldn't have started from here at all. But he was deeply irritated - just as overtures were being made to him about possibly rejoining the new Tory fold via a by-election - that the Shadow Cabinet hardened its anti-EMU policy. More important, having come to the conclusion that EMU will happen - and that it will be the most important change in international economic relations since Bretton Woods - he rightly regards it as crazy for the Tory party to adopt a programme that depends for its success on EMU crashing in ignominious failure round Europe's, and therefore inevitably to a large extent round Britain's, ears. This matters, and not only to the Tory party.
As a politician who looks to the future, Patten has made it much more difficult for those round Hague to claim that the pro-Europeans, such as Clarke, are embracing an obsolete Toryism. But one of the lessons for the Prime Minister is that a consensus is building here that is starting to look distinctly formidable, even in comparison with the Conrad Black- Rupert Murdoch axis of which he has been so wary. It is an alliance which is there to be deployed if and when Blair himself uses the EU presidency to shift public opinion towards Europe, including the single currency. If Blair reads the letter right, he will be just a little bolder than he has so far been. And for all the Tory leadership's brave attempt to gloss over the letter, Hague should worry. It was one more sign that his European policy will end up on the wrong side of history.