THE looming “catastrophe” of France and the Netherlands rejecting the European constitution is causing alarm in Brussels and apocalyptic warnings about the future of the European Union.

Debate is raging about what to do if the French vote “no” on May 29, but there is a growing consensus that it would be a turning point, marking the end of 50 years of “ever closer union”, threatening the single currency and halting enlargement, particularly for Turkey.

Some predict the EU’s fragmentation, with groups of member states increasingly banding together to pursue pet projects. Romano Prodi, the former European Commission President, said yesterday that a rejection by France, a founder member of the EU, would prompt the “fall of Europe”.

Peter Mandelson, the European Trade Commissioner, said that the best to be hoped for was stagnation. The Latvian President suggested that her country might not join the single currency.

On Saturday, the European Commission met to discuss how to rekindle public confidence in EU institutions, which was the original point of the constitution. The French vote is not on the agenda of the EU foreign ministers’ meeting in Luxembourg today, but it is bound to be discussed informally.

Two polls over the weekend showed that the “no” campaigns are gaining ground in France and the Netherlands, which votes three days later. More than 20 successive polls have predicted that the French will reject the constitution. The latest put the “no” vote at 62 per cent, the highest yet. The latest Dutch poll showed 52 per cent planning to vote “no”.

On Friday the Commission admitted that it was concerned for the first time. “It is very clear that the Commission, like everybody else, is worried by the turn of the statistics,” a spokeswoman said.

Signor Prodi went further, telling a French newspaper that if France rejected the treaty “there will be no more Europe”.

“The problem will not only be a catastrophe for France, but the fall of Europe. A ‘no’ would be catastrophic for economic and social Europe, not only political Europe. Everyone knows very well that there is no Europe without France,” he said.

Mr Mandelson, speaking in the Netherlands, said: “Europe will not fall apart, but it will be a setback if the constitutional treaty is rejected. At best, it would stagnate; at worst, we would see some form of chaos. It could have damaging economic consequences.”

Charles Grant, director of the Centre for European Reform, said that, just as France was the driving force behind the creation of the EU, so it might also be the country that slams on the brakes to closer union and enlargement. “The French referendum could mean this is the year that the widening and the deepening of the EU stopped,” he said.

The Presidents of Finland, Austria, Portugal and Latvia, who met over the weekend, agreed that a French “no” vote was a European problem. President Fischer of Austria said: “We all agree that the ratification of the European constitution is very important. It’s not good for Europe if we have problems in that field.”

President Vike-Freiberga of Latvia appeared to support warnings from Norbert Walter, the Deutsche Bank chief economist, that a French “no” would dissuade new EU members from joining the euro.

The ten mainly eastern European countries that joined the Union last year are required to adopt the euro as soon as they are ready, but Mrs Vike-Freiberga said: “The markets are already getting nervous about the future of the euro. Latvia, as a country that was planning to join the euro on January 1, 2008, is, of course, concerned about anything that is going to weaken or throw into misbalance the solidity of this currency.”

European leaders openly disagree on whether other countries should ratify the treaty if France and the Netherlands reject it. Jean Claude-Junker, the Prime Minister of Luxembourg, which holds the rotating EU presidency, said last week that the ratification process should continue. The European Commission concurred but countries that expect to have trouble winning a referendum , particularly Britain, will be reluctant to campaign for endorsement of a treaty rejected by others.

EU leaders have never agreed a “plan B” if the constitution is rejected, although the default position is that the EU will continue to be run under the Treaty of Nice. This will be discussed by heads of state at a summit in June, but diplomats are considering extracting less contentious parts of the constitution and implementing them as amendments to existing treaties.

• Lionel Jospin, the former French Prime Minister, emerged from three years of political exile at the weekend to denounce fellow Socialists who want to reject the European constitution.

  They had a duty to vote “yes” because the party had decided to do so in an internal referendum last December, M Jospin told a rally for the 100th anniversary of the French party. He said that Laurent Fabius, also a former Prime Minister, and other senior Socialists who have broken with the party line were “ inspired by individualism” rather than “the collective spirit at the core of socialism”.

  The rejectionist mood is seen by all parties as a reflection of French public anger towards the Parisian Establishment.

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