On Saturday in Brussels the heads of government of the European Union will select the countries which will participate in the introduction of the single currency and the rates at which currencies will enter it on January 1st next.

These are momentous decisions that mark a decisive point of no return in the process, the last major political intervention before the automatic provisions of the Treaty of Maastricht and the central bankers take over.

But unlike the tantalising wait for history to be written in the North on Good Friday, this process is not supposed to be about surprises. We know what will happen. Eleven countries, Ireland included, will be given the go-ahead as having met the Maastricht convergence criteria, and the central ERM rates will almost certainly be used as the reference for fixing the rates.

For months now the Economic Affairs Commissioner, Mr Yves Thibault de Silguy, has repeated his maxim, "No surprises". Indeed, the May 2nd meeting was itself a product of ministerial concern last autumn in Mondorf in Luxembourg to take any element of uncertainty out of the markets by announcing key decisions in advance.

But a dark cloud of uncertainty is now hanging over the weekend in the form of the appointment of the president of the European Central Bank, a row that bodes ill for perceptions of the single currency launch precisely because it is not about fundamental differences of economic or political approach.

The only two candidates in the field at present, the Dutchman, Mr Wim Duisenberg, and Mr Jean Claude Trichet, of France, are eminently qualified and both, by common consent, from the hard-currency school of central bankers.

The inauguration of the ECB is to be made in July, and thus the appointment does not technically have to be made this weekend, although parliamentary scrutiny will require some time. The French are suggesting, some would say self-servingly, that a postponement of the decision until after the Dutch election on May 6th could make matter easier. Not so, say the Dutch.

But failure to reach a decision on the issue this weekend will be seen by many as a sign that despite its treaty-guaranteed independence the ECB is in danger of becoming a political football even before it opens, a victim of competing national pretensions that have little to do with the good of the single currency.

The contest has turned into a classic piece of brinkmanship by both sides with the Dutch Prime Minister, Mr Wim Kok, hinting strongly on radio 10 days ago that he will "give the French a dose of their own medicine" and veto Mr Trichet if the French block his man.

For the Dutch the whole row has a terrible, nightmarish sense of deja vu. In 1994 Ruud Lubbers looked a shoo-in for the job of replacing Jacques Delors as President of the Commission. But suddenly the German Chancellor, Helmut Kohl, to the surprise of all, announced that he would not be acceptable to Bonn. Lubbers had committed the unpardonable sin of opposing German unification some years before.

There was no way round the veto and so, to his own intense surprise and Dutch fury, Jacques Santer got the call.

Duisenberg's appointment at the Dublin summit in 1996 to the presidency of the European Monetary Institute, the precursor of the European Central Bank, had been seen by most finance ministers as a clear sign that there would be a seamless transition in institutional and personnel terms. That was certainly the impression of the then Irish minister, Ruairi Quinn.

But even then Jacques Chirac had ostentatiously demanded that the minutes record formally that the decision was not to be seen as pre-empting the ECB appointment.

Some of this row, it appears, is about the insatiable desire of the French to see their man at the head of every financial institution in the world. Michel Camdessus heads the IMF, which he took over from Jacques Larosiere, who now heads the European Bank for Reconstruction and Development, which he in turn took over from Jacques Attali. That post is up for grabs again and is likely to go to a Frenchman if Trichet doesn't get the ECB.

The French have let it be known they believe an implicit deal was done with the Germans for a French presidency of the ECB when the bank was located in Frankfurt, a contention hotly denied by Bonn which is strongly supporting Duisenberg.

Yet another ingredient is the Chirac grand-standing style. Determined to see France at the centre stage of Europe he has embroiled the country in a series of unwinnable battles with his European partners. No French finesse here: instead of the rapier Chirac wields the double-headed axe. Yet his tactics could effectively result in the defeat through mutual veto of both the two best-qualified candidates for one of the key jobs in Europe.

This time, sources say, his nomination of Trichet, whom he does not get on with, took the candidate himself by surprise - he apparently would quite like the job but is not nearly as bothered about it as his president - and bumped the Socialist government into an international row it did not particularly want.

Attempts to broker a compromise, despite many false dawns, appear so far to have failed. The best chance is understood to be an implicit agreement that Duisenberg gets the job but retires early after half his eight-year term to be succeeded by Trichet, who will serve until then as an ordinary member of the executive board of six.

(An offer to appoint him as vice-president in this context is unlikely as it, unlike ordinary membership of the board, is a four-year non-renewable term).

The problem with such a deal is that Duisenberg has made it clear he views such a package not only unappealing to himself but damaging to the credibility of the bank.

The sense of a cosy, back-room, political deal between the big players is also anathema to many smaller member states. Charlie Mc Creevy is not alone in complaining that he hasn't a clue what is going on. But it would also undermine the bank president's treaty-guaranteed eight-year mandate and hence his independence from political influence, the last message the bank wants to send out this weekend. Nor do leaders want this weekend's media fest to be dominated by the failure to agree on this issue. Markets will not take that kindly.

And, just because the British, although in the chair, do not have a vote on the issue because of their non-involvement in the introduction of the euro - the reason that the meeting is being held in Brussels - that does not mean they will not take some of the flak for failure.

Their apparent unwillingness to get involved in banging heads together to get a deal reflects poorly on their supposed desire to assume the leadership of Europe. The time has come for London to show its mettle.

As for Ireland and its potential candidate, Maurice O'Connell, a man who could certainly garner not a few votes in a deadlock, the word is that he has no interest in leaving Dublin for Frankfurt. Even the executive board, it appears, has no appeal.