Mr Blair remains a cautious soul - and not without good reason

THE PRE-EVENT publicity insisted that at 3.30pm precisely yesterday, Tony Blair would cross the Rubicon of Britain's membership of the single currency. The way back would be barred: our fate would be sealed and doubters banished to the fringes of polite society. As an inhabitant of that slim intersection on the Venn diagram of politics which houses centre-left EMU-sceptics, I huddled miserably in front of the television set awaiting the moment when my cautious counsel would finally be dashed against the steely convictions of the Prime Minister.

It turned out to be a far less horrible experience than I imagined. The Rubicon stands where it stood. The only difference is that Mr Blair has said that before deciding whether or not we will cross it, he will ensure that he has very expensive equipment, just in case.

Not that it is being spun that way. Mr Blair's spokesman has already pronounced on the question of whether our policy on entry is "if" or "when" with the interesting ruse of declaring the two words interchangeable (he might consider briefing in German next time, a language in which they are). The psychological impact of a statement of the possible benefits of Britain's EMU membership made by the Prime Minister at a time of his own choosing is intended to move public opinion towards membership. That much is clear. But this is not the occasion for Europhiles to hang out the blue and yellow bunting. Mr Blair has opened only one of his ears to their persuasions. He chose his words very carefully and nowhere did he say that he was unconditionally in favour of membership. Indeed, the reiteration of the benefits of a "successful single currency" served to raise the unnerving spectre of an unsuccessful one.

Nor did the Prime Minister depart from the commitment to convergence tests laid out in October 1997 by the Chancellor. There was no attempt to argue, as many proponents of early entry do, that our economy will converge naturally with others once Britain is set on an irrevocable course of joining, or that the tests should be waived in the service of the Great European Cause

The Government's stated position has not changed one jot. The real purpose of yesterday's exercise was to test whether the appearance of momentum at the top will move public opinion to a point where Mr Blair would feel ready to risk his authority on fully backing British entry. Hence the announcement of a national changeover plan to ensure that we are ready to use the euro in 2001 or 2002. Once central payments systems, Inland Revenue operations and Customs and Excise have been prepared, at great cost and effort, for the demise of the pound, there will be a referendum to see whether we really want to get rid of it at all.

Conventional practice and good housekeeping, to say nothing of democratic transparency, might suggest that things should be done the other way around, with the referendum first and the implementation later. Naturally, though, there is method in Mr Blair's madness. There always is. The topsy-turvy procedure betrays the Government's fear that popular scepticism about the euro is not dissolving, and that even after the full artillery assault of a referendum campaign there will still be too high a risk of that New Labour unthinkable: a defeat.

Far from being, as vaunted, a brave commitment to the euro, this is a continuation of the policy of stealth by other means. Pro-EMU voices in business, politics and the media who have been pleading and nagging, with all the earnestness of trainspotters, for an exact timetable of British entry, underestimated Mr Blair's natural caution. The Prime Minister is acutely aware that this is the first major change in the UK's circumstances over whose consequences he has little control.

For all the sound and fury of the argument, neither side knows whether EMU can be kept on the road, what the sacrifices will be, and whether they are worth making.

This was the point that William Hague was making rather well in his reply, until he became side-tracked by the temptation to bang on about "a thousand years of history" - which was a fustian soundbite when Gaitskell first used it to attack the Common Market in the Fifties, and is best left out of reasoned debates about the future of Europe in 1999.

Unlike the French and German governments, which had not the slightest intention of letting their voters interfere with the will of their politicians, the citizens of the UK expect a vote on the most significant and far-reaching event in national life since the war. So there is nothing inevitable about entry.

The watchful eye of Alastair Campbell has been monitoring the opinion polls and heeding their warnings. After the launch of economic and monetary union on New Year's Day, the best PR event for the euro because it seemed to herald a success while not in fact risking failure, the next major poll showed 52 per cent in favour of the UK joining EMU and 29 per cent against, with 19 per cent undecided.

At the same time, leading EU figures are becoming far bolder in trumpeting the political nature of the single currency - which New Labour has hitherto sought to play down - on the grounds that the euro is easier to sell to the British public than the creation of a supra-institution to run it.

For the first time yesterday, Mr Blair conceded a political dimension without specifying what it might be. He might consider Oskar Lafontaine's recent statement: "The European Central Bank has the primary objective of maintaining price stability but without prejudice to this objective, it is obliged to support economic growth along with high levels of employment and social protection."

As Kant remarked, "The great goods cannot live together." Mr Lafontaine simply cannot have everything he says he wants. It does prejudice the "key objective" of pursuing low inflation if this aim is accompanied by the other aspirations laid out by the German Finance Minister. The only sense his declaration makes is as a plea for governments to have the right to interfere with the objective-setting of the ECB.

My question to Mr Blair is: what does he think about this? Does he want the UK to be in a euro zone run by independent bankers ruthlessly running a single-interest-rate policy whatever the circumstances in the member states, but free of political constraints?

Or does he concede Mr Lafontaine's point that governments should get involved in running the single currency, and if so, how does heavily does he think that Britain's influence will weigh against other interests? None of these questions was answered yesterday. Nor will they go away. The Rubicon is a lot wider and more turbulent than those who urge us to wade in with haste have realised.