How can Blair refuse a referendum for so great a change as the European constitution?

He is easily seduced by European projects: so much more satisfying than the frustration of domestic matters

Last December, the European constitution seemed to be in trouble. Admittedly, the negotiations had only broken down over Spanish and Polish voting rights, which was hardly a basic principle. It could surely be resolved over a vigorous haggle in the souk. Even so, there was no enthusiasm for restarting the talks. The rock had rolled a long way downhill.

Last December, the European constitution seemed to be in trouble. Admittedly, the negotiations had only broken down over Spanish and Polish voting rights, which was hardly a basic principle. It could surely be resolved over a vigorous haggle in the souk. Even so, there was no enthusiasm for restarting the talks. The rock had rolled a long way downhill.

Bombs move rocks. After the Spanish Election, everything changed. The new government was determined to assert its European credentials; the Poles were not prepared to stand alone; the Irish saw a chance to end their six-month EU presidency with a flourish. Initially, even some EU ambassadors assumed that this would be unwelcome in Number 10. Tony Blair had believed that the constitution was safely concealed in the long grass, at least until after the next UK election. Now, it was back in full view, confronting him with a choice: give up trying to be a good European or face the one electoral embarrassment that could jeopardise his third term.

Yet Mr Blair shows no signs of being embarrassed. He was not kissed by Muammar Gaddafi; he now seems happy to embrace Valéry Giscard d'Estaing's constitution and to face down the demands for a referendum.

Those will be clamorous, and with good reason. If the EU constitution were adopted, the UK would have a written constitution for the first time in its history; one drafted with a minimal British contribution, after a complete absence of public debate.

The EU constitution is long, ill-written and imprecise. But in its present form, it would open up almost every area of government policy to legislation at an EU level. The Union would co-ordinate the social, economic and employment policies of its member states. It would have extensive new powers in foreign affairs, defence, criminal justice and policing matters. The scope for national vetoes would be greatly reduced.

In recent years, the EU has become much more powerful. It no longer resembles the Common Market which the British people thought that they were voting for in 1975. But it is still - just - an association of sovereign states which co-operate for common purposes. With the new constitution, that would no longer be the case. A new state would have been created: a super state.

Moreover, in other countries with written constitutions, legal arguments are ultimately resolved in a supreme court whose judges are citizens of the nation concerned. Sometimes, there is a political input into their appointment. In the case of the European Court of Justice (ECJ), this would not apply. Vital decisions about our future would be taken by foreign judges with no background in British law; no personal interest in our rights and freedoms.

It can also be guaranteed that whenever the constitution's language was ambiguous - expect plenty of that - the ECJ would interpret it in a federalising direction. Throughout the history of Britain's relations with Europe, we have always found that the obligations which we incurred turned out to be far greater than we had thought. But all of that would be utterly insignificant compared to the scope of the new constitution. If it were implemented, then in great areas of public policy, we would no longer know how extensive the British Government's powers were. We would only know that they were much less extensive than they had been and were due for a further, steady diminution.

The Government insists that it has drawn red lines, and would not accept any constitution which breached them. But it is late in the day to secure any substantial amendments to the present text, especially as other governments now seem determined to bring their negotiations to a speedy climax. It may be that Mr Blair will secure concessions on foreign affairs and direct taxation. But even if he did, he would be signing up to a constitution for a federal Europe.

The damage to Britain is self evident. But the new entrants to the EU could also suffer serious consequences. It is easy to see why their political elites should be attracted by Europe. In many cases, their 20th century history was one of backwardness, dictatorships, foreign occupation and war. No wonder that they wish to join an EU which seems to symbolise modernity, prosperity and peace.

That reaction is understandable, but it could be dangerous. In order to entrench their liberties, these newly free peoples need to learn to exercise their political rights. They even need to be allowed to make their own mistakes.

But if they subscribed to the EU constitution, they would rapidly discover that their democratic rights are as valuable as Soviet-era banknotes. Their response may not be acquiescent. After less than two decades of being unable to sack a government which they disliked, the Scots became so upset that the stability of the UK was threatened. If the Eastern Europeans found that their ability to exercise their long-desired freedom to govern themselves was a brief interlude between Comecon and Eurocon, there could eventually be trouble.

Mr Blair is oblivious to these risks because he knows no history. He is easily seduced by grand European projects: so much more satisfying than the frustration of British domestic matters. It must also be remembered that even if Mr Blair is not a socialist, he is typical of a certain type of Anglo-American leftist, in that he dislikes his own country's traditions and its past. For him, Europe is a way of turning Britain into another country.

The French and the Germans may know more about the past than Mr Blair does, but they want to forget their own recent history. They are still trying to make love on the psychiatrist's couch. The Germans wish to escape from the guilt of their militarism; the French, from the humiliation of theirs. The result is yet another attempt to run Europe as a French jockey on a German horse.

Yet Mr Blair still insists that the constitution is a mere tidying up exercise. He will have difficulty finding a single serious continental European who agrees. In several European countries, a change of this magnitude would require a referendum. The Germans, of course, cannot have one; their constitution prohibits it. When it was written, in the immediate post-war years, the drafters felt that the people who had elected Hitler could not be trusted with plebiscitary democracy.

That hardly applies to the people who stood alone against Hitler. There are those who insist that referendums have never been part of the British constitution. But it could be argued that this objection is out of date. One of the glories of our unwritten constitution is its ability to evolve. Over the past few decades, it has become customary to refer constitutional questions to referendums.

It is a bit late for Mr Blair to pose as the custodian of constitutional propriety. He is refusing to hold a referendum for only one reason: he knows that he would lose it. If he persists in this defiance, he may very well find that instead, he loses an election.