PARIS -- European leaders yesterday held out hope that they could move forward with their decades-long drive to unify the continent under a single economic and political banner, but braced for a potentially fatal setback as Dutch voters threatened to join France in rejecting a proposed constitution.
After vowing initially to press ahead despite the defeat in France, leaders of the European Union said they would wait for the results of a referendum tomorrow in the Netherlands, where opinion polls indicated the constitution was in trouble.
Officials said they would decide what to do next during a previously scheduled summit in Brussels on June 16-17.
The French vote shook the government in Paris, where President Jacques Chirac was closeted in Elysee Palace to consult with advisers on a planned Cabinet shake-up. His staff issued a statement announcing he would address the nation on television tonight to disclose ''decisions regarding the government."
In the aftermath of the 55 percent vote against the constitution, the palace declined to respond to French media reports that Chirac had decided to sack Prime Minister Jean-Pierre Raffarin, whose aides cleared out their offices yesterday in anticipation of such a move. Raffarin met with Chirac for 30 minutes, and aides said he offered his resignation.
Negotiators settled last year on the language of the constitution, which is intended to create a uniform legal framework that would give broad power to the European central government on issues of foreign and domestic concern. Since then, countries have been deciding one by one whether to ratify the document.
As opinion polls indicated rejection of the referendum in France in the days leading up to the vote, some European leaders held out hope the French could be pressured into trying again if they ended up as the lone holdouts. But with surveys indicating the Netherlands was also poised to vote no, politicians supporting the constitution changed their tone and began talking about the necessity of respecting the wishes of the people.
In Brussels, the headquarters of the EU, leaders tried to soldier on but had trouble mustering much enthusiasm.
''We cannot say the treaty is dead," said Jose Manuel Barroso, president of the European Commission, even as he acknowledged the defeat in France was a ''serious problem" and offered no prescription for fixing it. Leaders said they had no alternative strategy drawn up if the constitution was not enacted.
Each of the EU's 25 member nations must approve the constitution before it can take effect. Nine countries -- Austria, Hungary, Italy, Germany, Greece, Lithuania, Slovakia, Slovenia, and Spain -- have ratified it so far.
Opponents of the constitution said drafters need to rewrite it to win French support. ''I'm European, but I want a strong, unified Europe," Laurent Fabius, a Socialist leader who broke from his party to fight the document, said on French television.
''The constitution didn't do that."
Prime Minister Tony Blair of Britain called for ''a period of reflection" after the rejection by France. He said the debate had failed to take into account people's anxieties over how an expanded and more powerful European central government would affect job security, immigration, and questions of national identity.
He said the constitution was a ''perfectly sensible set of rules to govern Europe," but added that there was ''a bigger debate now in Europe."
Blair said yesterday that it was too early to tell whether Britain would go ahead with a referendum on the constitution as planned, calling for a ''time for reflection." No date has been set for that vote.
Even countries that have already ratified the measure harbored doubts that the French rejection could be overcome. ''This is regrettable and will cause great challenges for Europe," said Foreign Minister Joschka Fischer of Germany, which adopted the constitution in a parliamentary vote last week.
Chirac, meanwhile, ignored calls from the opposition to quit, but political analysts said his popularity was so low it was unlikely he would revive a push to pass the constitution before his term ends in 2007. He is not expected to seek a third term, partly because of his age; he will turn 73 in November.
Material from the Associated Press was included in this report.