By Henri Astier
BBC News, Strasbourg
In the popular Asterix comic books - which contain many light-hearted references to French public life - disputes often end up with half of the Gallic village at the other half's throat.
Strasbourg baker Marie Bildstein quietly supports the constitution
In recent weeks the debate about the proposed EU constitution has been as divisive as anything found in Asterix.
Unusually, however, France is not split along political lines.
The main parties of the right and left are both urging supporters to vote "Yes" in Sunday's referendum. The main division is social.
The Gallic village is divided between those relatively content with their lot and those Prime Minister Jean-Pierre Raffarin once called "la France d'en bas" - disaffected people at the lower end of the economic ladder.
Polls suggest that the "Yes" vote is strong among professionals, businessmen and the middle classes.
Workers, junior employees, farmers, and those generally worried about the future by and large intend to vote "No".
A deep sense of dissatisfaction with the elites - of "us versus them" - is palpable when you speak to many ordinary people up and down the country.
"This constitution has been imposed on us," says Jean-Loup Dechezlepretre, a technician from the central city of Clermont-Ferrand. "We feel like outsiders."
Evelyne Faigel, an unemployed secretary from the Paris area, says: "I find it difficult to pay for crucial things like housing, healthcare and food. I am worried about the future and feel the way Europe is headed will not help."
Many are particularly concerned about integrating with European countries that do not share France's commitment to a generous welfare state.
Christian Lebosse, a bartender in Nantes, says: "Our social system is being undermined by other European countries. I talk about it with customers. Ordinary folk are against [the constitution]."
"The elites live in their own bubble," says Patrick Merck, a tobacconist from Strasbourg who has founded a political movement pointedly called La France d'en Bas.
Mr Merck's complaint could have been echoed by many on the far left or the far right.
"No" posters in Strasbourg: Many grievances are being aired
His sympathies, as it happens, lie with the centre right. But again, the "No" vote is driven not by politics, but by a feeling of helplessness.
As a result, many votes on Sunday will reflect particular grievances and a sense that those in charge are not listening.
To those campaigning for a "Yes" vote, such extraneous issues are distractions. They are urging people to vote purely on the text of the constitution itself.
Robert Herrmann, a socialist leader in Strasbourg and a strong supporter of the treaty, notes that historically, French governments have used referendums as plebiscites designed to boost their support.
No wonder, then, that people treat the vote as a verdict on an increasingly unpopular administration.
The referendum, Mr Herrmann concludes, was a mistake. "The right forum to discuss the EU constitution was parliament," he says.
But it is by no means certain that popular grievances will translate into a defeat for the constitution on Sunday.
"No" may be the answer you say out loud, and the one you read on many posters stuck by angry activists on city walls.
But the "Yes" camp can take heart from two factors.
The first is that leading parties and the mainstream media have been stressing over and over again that the issue at hand is Europe, and nothing else.
A large number of people are taking this message on board - even in rural areas where angry farmers have been agitating against the treaty.
"This referendum is not about Europe's Common Agricultural Policy," says Jean Castagnini, a farmer near Clermont-Ferrand who says he will vote "Yes".
He may be in the minority among peasants - but perhaps not in the French population as a whole.
The second encouraging factor for the pro-treaty camp is that although the naysayers speak loudly, many people may be leaning towards a "Yes" vote without saying so.
One such silent supporter is Marie Bildstein, a baker in Strasbourg: "I only hear the opinions of customers who say 'No' - I'm not sure how many feel the same as me, but there must be quite a few."
The result of Sunday's vote will hinge on exactly how many people belong to the quieter of France's two squabbling groups.
More stories by Henri Astier on French opinion ahead of the referendum: