The EU scrambled Monday to pick up the pieces after a devastating French "no" to its new constitution -- while bracing for a Dutch vote that could deal a killer blow to its long-cherished integration blueprint.

European Union leaders called for a "pause for reflection", as opinion polls showed that Dutch voters will probably emulate those in France, who voted by some 55 percent to 45 percent on Sunday to reject the constitutional treaty.

The European Commission, the EU's executive arm, said it accepted the decision of the French people but appeared ready to weather this week's storm and wait for the bloc's leaders to meet in mid-June to discuss what went wrong.

"It's important to analyse what happened in France, it's important to understand the message, it's important to understand it in all its detail," said commission spokeswoman Francoise Le Bail.

A June 16-17 summit is certain to become a crisis meeting, as the leaders try to adjust to developments and stop the rot ahead of other referendums later this year in Luxembourg, Denmark and Portugal.

But with the treaty technically legally dead, Le Bail pointed out that part of the text, Declaration 30, allows for leaders to discuss how to proceed if at least three-quarters of the Union's 25 members ratify it.

That aside, she said, the EU can still function as it does now using the Nice Treaty.

The constitution is aimed at giving the EU a framework for streamlined decision-making following its enlargement a year ago to include 10 mostly ex-communist central and eastern European countries.

It also aims to boost the EU's profile with a president and foreign minister.

France's decision to resoundingly reject the treaty after it was painstakingly assembled by 300 experts from across the political front lines, was met with surprise and occasional bitterness by European officials.

"The majority voted against, but for what reasons? Some of those reasons are contradictory," commission head Jose Manuel Barroso told French television overnight.

"Some say Europe goes too far, others say that they want a different kind of Europe, others still say, 'We want more of Europe, but not this Europe'."

EU foreign policy chief Javier Solana voiced respect for the French decision and vowed to work to keep Brussels on the world stage, but his remarks too were tinged with regret.

"Europe needs its people, but each one of us also needs her. Europe is, above all else, a venture of hope," he said in a statement on Monday.

The question now is what can be salvaged.

Nine countries, accounting for almost half the EU's population, have ratified the treaty but all the members have to approve it for the constitution to gain the force of law.

However French President Jacques Chirac, in an address to the nation after the referendum, implicitly urged his European partners to move ahead, making Wednesday's referendum in the Netherlands more crucial than ever.

"I think it's really a nail in the coffin of the constitutional treaty, to be honest," said Marco Incerti of the Brussels-based Centre for European Policy Studies. "With a French 'no' -- and a very strong French 'no' -- a Dutch 'no' is very likely."

Britain's Foreign Secretary Jack Straw seized on the implications for his country, where the treaty is, to say the least, controversial, and which takes over the EU presidency in July for what promises to be six months of turmoil.

He said that "the result raises profound questions for all of us about the future direction of Europe."

Prime Minister Tony Blair, on holiday in Italy, said it was too early to decide whether Britain would hold a referendum.

In Paris, President Jacques Chirac's office confirmed Monday that the "no" vote is to claim its first victims: the French leader is to announce a reshuffle Tuesday, with Prime Minister Jean-Pierre Raffarin heading for the door.