Somewhere at the heart of government sits a blueprint specifying a date for the euro referendum. It is May 1 2003. Naturally, it's only one notion. There are other possibilities, including no date at all. Nothing like a decision is near. But this is the one on which most work has been done. I've discussed it with ministers and officials. It dispels the idea, urged in a letter to the Guardian by an important group of Labour sceptics, that public services are far more important than the euro, and the referendum must be put off until they're fixed. That could yet prove to be the opposite of the truth.  Start working back from May 1, and you hit other deadlines. The campaign proper is reckoned to need two months. March and April would see it hammering away at full intensity. Before that, a preparatory campaign would unfold, in parallel with the parliamentary process of getting a referendum bill passed into law. Little problem in the Commons here, but the Lords would be another matter. That's where all those - Lord Owen, many Tories - whose strategy is to stop a referendum happening would make their last stand, filibustering about campaign finance and the wording of the question. The planners are allowing four months for that, which means starting in November - which means, in turn, settlement of the five economic tests by October, maybe before the party conference.   This is an adventurous programme, faster than most people are aware of. I happen to believe that, unless it's   adopted, there will be no referendum in this parliament. It would maximise the political opportunity, and just about enable the whole euro deal, including notes and coins, to be completed before the next election. But that's a personal opinion. The relevant political fact is that important ministers are very sure they can hold and win a referendum within that time, or by autumn at the latest, and thus secure an historic achievement for the Blair administration.   No other scenario offers such an incontestable triumph. This is painfully obvious from the first month's activities of this year, in which ministers have set themselves life-or-death tests they have no hope of conclusively winning. Two weeks ago, Stephen Byers staked his future on "the quality of your travelling experience". If this hasn't greatly improved, he said, he would deserve to be punished at the election. On Sunday, Tony Blair vowed more explicitly to fall on his sword if the NHS isn't "basically fixed" by the next election. "I am quite happy to suffer the consequences," he said. "I am quite willing to be held to account by the voters if we fail."   These were the words of desperate, perhaps complacent, certainly pious politicians. They used the strongest language they could think of to reflect the perception of failure in which they fear they're now engulfed. They wouldn't have spoken thus unless they thought they could deliver. Yet, far from launching a supreme national effort to make the trains run on time and the hospitals im prove beyond recognition, these promises are likely to inaugurate an era of dismal politics.   For the pledges are never provable. It's quite conceivable that the railways will respond to three years of consistently enhanced investment. It's possible that the NHS will deliver improved statistics in some parts of the country, or even nationwide. But the argument about their meaning will never end. Last week was an acrid foretaste of the years to come, with ministers pointing to abstract figures that purport to show improvement, and other people - patients, families, doctors, nurses, Conservative politicians, bloody-minded journalists - deploying the singular human disasters that will be available every day of the week to show the opposite.    What we have to look forward to from a political era staked entirely to public sector performance is, in other words, a battle of the spinners more utterly bewildering than ever before. Even if delivery does improve, there'll be myriad stories that say otherwise. Even if 86% of people still claim to be satisfied with the NHS, everyone knows this figure is distorted by gratitude,   loyalty and fear of complaining, for everyone has experiences, of delay especially, that make satisfaction entirely inappropriate. The politics of this will turn far more on the general credibility of the parties than on the specific funding each purports to offer: because funding promises seldom link into the felt lives of voters. The claim that the NHS has been "fixed", or that travel is now "improved", will remain profoundly disputable until the day of the election.   There's not much joy in that for anyone. It's vital that the investment goes on, but the political excitement it's capable of generating is limited. For Mr Blair to be expelled from power because he's failed to fix the NHS is no more credible than him being kept in power because he can show a couple of thousand more acute hospital beds and a useful rise in nurse recruitment. Essential though better trains and schools and hospitals are, the heart must sink - and the electoral turnout too - at the prospect of three years' futile argument between rival narratives that are both incurably mendacious.   A referendum on the euro will be, by contrast, a clear-cut political contest. For a start, it's something the government promised at the last election. The need for it, to detoxify British politics, becomes ever clearer. The demand for a British decision, one way or the other, becomes more pressing as the years go by, and the weakness of the strongest government in Europe failing to provide one becomes more embarrassing, more subject to tacit peer-  group contempt, with each month that the single currency defies the hostility of those who thought it could never happen and/or never work.   But the case for a referendum is not just to fulfil some textbook idea of decent political conduct. I'm not that crazy. The case revolves round Labour's need for a project the voters can understand, to establish a raison d'tre that has some chance of being manifestly fulfilled. Improving public services does not fill that ticket. It's good work, essential work, work governments should be doing anyway. If it doesn't happen over the next decade, the so-called fourth largest economy in the world will look thoroughly sick. But as New-verging-on-Old Labour's Big Idea, its outcome will be indistinct and its claim on history trivial.   Pace Lord Healey and his friends the sceptic letter-writers, it certainly isn't an alternative to a euro referendum. The two can run alongside. They will need to. Awaiting public-service perfection is just another pretext for never putting the euro to the people. The opposite case is more positive than that. Winning the referendum won't be easy. But it's already more plausible than it was a month ago. It's the challenge a serious party can no longer duck, for the sake of its own standing. Far from the referendum making service delivery harder, it is Labour's only route away from lassitude, denial, and a verdict that says permanently and on everything: not proven.