Mr Blair has the chance to forge a new consensus

The constitutional treaty - the magnum opus intended to lay the foundation of the European Union of the future - is now dead and gone. If the slightest doubt remained after the French vote on Sunday, it was dispelled by the voters of the Netherlands.

The constitutional treaty - the magnum opus intended to lay the foundation of the European Union of the future - is now dead and gone. If the slightest doubt remained after the French vote on Sunday, it was dispelled by the voters of the Netherlands.

Propriety prevented the treaty being officially written off before the Dutch had voted. The only question now is who will be first to make the death official, and how will it be done? Will it come from the European Commission, will one or other national leader venture to speak for the rest (at the risk of drawing recriminations), or will it be a collective announcement at the European summit in two weeks' time?

The certainty is that there will be no British referendum. As ministers said gnomically before the French had voted, the British were absolutely guaranteed their say in a referendum - unless there was no treaty to vote on. That point has surely now been reached.

The advantage for Mr Blair in not holding a referendum is obvious. And while it is tempting to say that Britain would have benefited from a free and frank debate about Europe of the sort that captivated France in recent weeks, there were risks as well. There was also the small matter of whether a constitutional treaty was a suitable subject for a referendum in a country where such decisions are traditionally made by Parliament.

But there are disadvantages for Mr Blair in the referendum results as well, chief among them the timing. Britain takes over the European presidency on 1 July, at a time when the Union finds itself suddenly, and unexpectedly, at a crossroads. The way forward is not at all apparent - not least because the reasons for the French and Dutch rejections have been so disparate.

In both countries, the "no" vote combined a host of factors, from dissatisfaction with the current state of their countries and their present governments to the effects, as they saw them, of Europe's rapid expansion. The far right in France joined with the communists and socialist left to reject a treaty they saw as representing the interests of a small élite. The Dutch middle class rejected the treaty in part because they felt the character of their country was changing in ways they found unacceptable. Others objected to the price rises and economic instability they associated with the euro. But while the votes reflected discontent with the status quo, it is hard to see them as calls for radical change along the lines of what has become known as the "British model".

Yet the British presidency need not be the barren six months that the "period of reflection" called for by both M. Chirac and Mr Blair might suggest. With so much in flux, Mr Blair has an opportunity to canvass, and even forge, a new consensus. This should include reviving the most urgent - and, as it happens, least controversial - reforms contained in the ill-fated treaty: the end to the rotating presidency and the appointment of a foreign minister, a "Mr Europe". The "no" votes have also illustrated the gap that voters feel separates them from Europe's institutions. Ways need to be found to address this "democratic deficit" as a priority.

This may mean that moves towards economic convergence are put on hold. This makes sense, if only because the new French government will be finding its feet, and both Germany and Italy are facing elections in the next year. The political complexion of Europe's largest countries could look rather different by December. It makes no sense for Britain to force the pace on change that will be longer lasting and more deeply rooted if it comes with a national democratic mandate.