In a highly symbolic move, Chirac replaced Jean-Pierre Raffarin, who had become the focus for massive public disenchantment with the center-right administration, with Dominique de Villepin, another close ally who had been interior minister.

The reshuffle was a response to Sunday's referendum on the European Union's first-ever constitution, when nearly 55 percent of French voters rejected the text despite Chirac's best efforts.

The defeat has slammed the brakes on the EU leadership's grand integration drive, throwing the bloc into crisis and triggering an anguished debate about its future direction.

Dutch 'no' expected

In the Netherlands, which holds its own referendum Wednesday, opinion polls show voters are also likely to reject the treaty, exposing -- as in France -- an apparent disconnect between a governing elite largely in favor of the text and a suspicious wider population.

Nevertheless, the EU commission in Brussels reiterated that it is not making any contingency plans. "There is still no plan B," said spokeswoman Francoise Le Bail. "We have to wait for the next step tomorrow evening."

EU leaders have a chance to regroup at a June 16-17 summit in Brussels but quite what they will be able to agree on then is unclear, with nine of the 25 countries having already ratified the treaty.

French influence

The constitution -- designed to streamline and harmonize how the expanding bloc is run -- must be ratified by every country to take effect.

Opinion polls suggest a 60 percent "no" vote in the Netherlands, with many swayed by the same gripes as the French -- opposition to EU enlargement, fear of identity loss and unhappiness with the government.

Dutch Prime Minister Jan Peter Balkenende urged voters to make up their own mind in the first national referendum in the Netherlands in two centuries. "France cannot tell us what to do," Balkenende said. "The Dutch shouldn't merely take the lead from the French, they must make their own choice."

A Dutch "no" could trigger a domino effect with at least six other nations also due to hold referendums later, including euroskeptic Britain, Poland and Denmark.

British Prime Minister Tony Blair appears to be steering away from holding his planned vote next year on the back of the French defeat and likely Dutch setback. Blair, whose country assumes the rotating EU presidency in July, has called for a "time for reflection" as Europe mulls where to go next, and the British media said he would call off a referendum if the Netherlands voted against the constitution.

Others worried

Articulating EU concerns, Hungarian Prime Minister Ferenc Gyurcsany warned that the bloc faced a "massive problem" if the Dutch rejected the constitution and Britain decided against a referendum.

"We know ... that after the French 'no' the chance the Dutch vote will be unsuccessful has greatly increased," he said in a radio interview.

If Britain then backed away from a referendum, "this will become a massive problem."

In Warsaw, President Aleksander Kwasniewski called for consultations in the next few days to allow it to take a "sovereign decision on the way and date of ratification."

One theoretical option would be to renegotiate the treaty and make it more palatable, but that has been rejected by leaders such as Danish Prime Minister Anders Fogh Rasmussen, whose country votes on September 27. He said it would be "senseless" to ask Danes to vote on a treaty that could be rewritten. "I will not accept that," he told reporters.