Voters in France turned out in large numbers Sunday for a key referendum on the European Union's first constitution — a charter that aims to pull nations together but has spawned bitter divisions threatening its passage.

Polls had suggested the French would reject the constitution, which must be ratified by all 25 EU member state before it can take effect in 2006.

A French "no" would in effect kill the charter, although the treaty says EU leaders will discuss what to do if, by October 2006, at least one nation has "encountered difficulties" getting it accepted. It is possible that another vote could be held.

But with initial turnout higher than expected Sunday, there was a glimmer of hope that previously undecided voters could propel the constitution to a surprise victory.

Nearly 42 million people were eligible to vote in the pivotal referendum.

President Jacques Chirac (search) and his wife, Bernadette, voted together in their home district in Sarran in the Correze region at the rural heart of France.

Prime Minister Jean-Pierre Raffarin (search) — the likely first political victim in the event of a "no" victory — voted with his wife in Chasseneuil-du-Poitou in western France.

"We are the European people who will decide its future," Raffarin said. "The French have a responsibility ... and they are assuming it with, it appears, a high level of engagement at polling stations."

Backers say the constitution, which EU leaders signed in October, would streamline EU operations and decision-making, make the bloc more accessible to its 450 million citizens, and give it a president and foreign minister so it can speak with one voice in world affairs.

Opponents fear it will strip nations of sovereignty and trigger an influx of cheap labor just as European powers such as France and Germany struggle to contain double-digit unemployment.

The Interior Ministry put turnout at 25 percent by noon Sunday — nearly 5 percent higher than that recorded during the same time frame in the last French referendum on Europe: 1992's Maastricht Treaty on European unity.

That referendum narrowly passed.

The 55,000 polling stations opened at 8 a.m. (2 a.m. EDT) and were to close at 8 p.m. (2 p.m. EDT), except in Paris and Lyon, where voting was to end at 10 p.m. (4 p.m. EDT). The first exit poll results were expected shortly thereafter.

About 1.5 million voters in France's overseas territories from the Caribbean to Polynesia cast ballots Saturday, with the results to be released after all voting concludes.

Voters carrying market baskets or dressed for church trickled into polling stations near the site where the Bastille prison — stormed at the start of the French Revolution — once stood in central Paris.

Across the Seine River, flyers promoting the "yes" vote carpeted the street and sidewalks in the Left Bank neighborhood of Montparnasse — testimony to the intense nature of the debate that gripped France.

"If you look at every sentence, every turn of phrase, practically every article has a mention of (financial) markets," Anne-Marie Latremoliere (search), a 57-year-old graphic designer, said after casting a "no" ballot at a polling station near the Bastille. "We want Europe to be a beautiful place, and this is certainly not it."

Her fear that the constitution will promote voracious capitalism on the continent, at the expense of social protections, is typical among "no" supporters.

Arnaud Senlis, 27, toting his 2-year-old son on his shoulders, was equally adamant about his "yes" vote.

"I never thought twice about it," he said, complaining that the debate "seemed more about national politics and politicians' personal ambitions than a real debate about Europe's future."

A collective French "oui" — coupled with approval in another referendum Wednesday in the Netherlands, where opposition is running at about 60 percent — could give the charter unstoppable momentum as a dozen other nations decide its fate in the coming months.

It already has been approved by nine nations.

But a "non" would resonate even more powerfully across the continent because, in 1951, Frenchmen Robert Schuman and Jean Monnet launched the six-nation European Coal and Steel Community, the precursor to today's EU.

The key to a French victory for the "yes" camp could lie in the hands of those deciding at the last minute — more than 20 percent of the electorate, according to polls.

Katia Volman, a 22-year-old student, was among them, but she cast a blank ballot, saying the issues were too complicated to fully digest.

"I had so many reasons to vote 'yes' or 'no,' so I left it blank, and that way I won't regret my decision two days later," she said.

The possibility that the EU's latest attempt to knit together its club of nations could wind up stillborn in polarized France had many wondering what might lie ahead.

"If there was to be a French 'no' vote — a serious big rejection of the treaty — followed by a rejection in the Netherlands, then I think that this treaty is in effect dead," said John Palmer, an analyst with the European Policy Center in Brussels, Belgium.

"The danger then would be that we would enter a period of profound stagnation, maybe for two, three or more years, until we have new elections in France and some of the other key countries."

Nine nations — Austria, Hungary, Italy, Germany, Greece, Lithuania, Slovakia, Slovenia and Spain — already have ratified it by referendum or parliamentary vote.

A defeat not only would shake the EU to its core, it could plunge France into political chaos. Chirac's prestige, at home and abroad, would be damaged; the opposition Socialist Party, divided down the middle, could be crippled; and the unpopular prime minister would, analysts agree, quickly be fired.

A French rejection of the treaty would make Chirac only the second leader, after Gen. Charles de Gaulle, to lose a referendum since the founding of the Fifth Republic in 1958.