Unsurprisingly, outrage immediately ensued from virtually every corner of society: parents, the local opposition, Muslim leaders and even the French Government. Marlène Schiappa, France's gender-equality minister, called Sanchez "a typical example of someone brandishing secularism as an anti-Muslim political weapon, or anti-Jewish for that matter".
Defending - some say mandating - pork is not specifically an argument about French purity. Sanchez's forebears were Spaniards; Van Gogh, now much admired, moved to neighbouring Arles from the Netherlands via Paris. The mayor says his push is about religion. His critics say it is about Islam.
"My decision is so that the Republic wins, that in France the Republic has priority and not religion," Sanchez said in an interview at Beaucaire's town hall, the entry of which featured a giant nativity display illuminated with twinkle lights even at midday. "I defend the principles of France. If sharia law is installed in France tomorrow, then there's no problem if it's the law. For now, the Republic is secular, and I don't know why pork should be a problem. If you don't want it, don't eat it."
For Muslim leaders, this is little more than a thinly veiled attack.
"I went to French public schools, and we never had this issue," said Yasser Louati, a prominent French civil liberties advocate and Muslim community organiser. "This is nothing more than a dog whistle, of saying things without actually having to say them. We know which community is targeted."
Sanchez, rejecting allegations that requiring pork targets particular minority groups, said, "I'm not stigmatising anyone. The people who don't eat pork are welcome to come into the cafeteria. They just choose not to eat it."
What students eat at school has become nothing less than an existential debate in France, where the state is officially neutral and, by consequence, public space is meant to be free of religious influence.
In that sense, the school cafeteria is now a courtroom, where a nation's interpretation of secularism - and the identity of a nation itself - are somehow on trial.
When seeking re-election in 2016, the former President Nicolas Sarkozy, once the leader of the centre-right Les Républicains party, put it this way: "If a little guy's family does not eat pork and the menu at the cafeteria is a slice of ham and fries, well, he skips the ham and eats a double helping of fries. In a republic, it's the same rule and the same menu for everyone."
Other municipal authorities - often from Sarkozy's party, not the National Front - have recently attempted to do the same as Sanchez. In 2015, for instance, the mayor of Chalon-sur-Saône, a town in Burgundy, likewise banned alternatives to pork - a move that a local court in 2017 later annulled, on the grounds that limiting options was not in the best interests of children. The Burgundy mayor vowed to appeal.
In recent years, French Muslims - citing the 2004 ban on hijabs in public schools, the 2010 ban on the face-covering burqa and the outcry over the "burkini" swimsuit in 2016 - have complained that efforts to ensure a neutral public space have often been crackdowns on Islam in the name of Republican ideals. To that end, President Emmanuel Macron cautioned in December against what he called "the radicalisation of secularism," a practice that in his view sees otherwise noble French values used for political ends.
"This is a fake problem," said Laure Cordelet, a local opposition leader in Beaucaire. "Frankly, if French identity is eating pork, we have a big problem."
The mayor's decision will probably affect about 150 of the 600 students enrolled in the district, she said. There is an important socio-economic issue at play, she added: many Muslim students are among the poorest in the local community, and requiring that pork be served means forcing them to forgo a "wholesome, balanced meal" one day a week.
For school meals, students in Beaucaire have to pay 2.40 euros per day, which means that Muslim students will now be paying for food they cannot eat.
"My issue is in fact that [Sanchez] seeks publicity for the National Front all throughout France, but does not think of the children here in Beaucaire," said Anne Moiroud, the head of the Beaucaire school district's parents' association. Sanchez has been a spokesperson for the far-right party since 2017. Moiroud and Cordelet held a protest picnic today in the square in front of Beaucaire's town hall, which drew between 150 and 200 people, according to local media.
On the whole, French educators do not see a problem in providing alternative meals in schools.
"This has been going on for decades with hardly any difficulty," said Ghislaine Hudson, a mediator for the Académie de Paris, the governing body for schools in the capital, and a former director of the Lycée Français in New York.
"Our objective as educators in the cafeterias is just to feed students, and for me it poses no problem when we serve alternatives to pork. And I believe the majority of teachers in most schools agree with that," she said.
Academics and legal analysts also condemn what they see as a wrongheaded interpretation of France's secular law.
"The Republic is not at all anti-religious. Laïcité just means that the state is neutral, which is entirely different," said Patrick Weil, a leading expert on the topic, which he explored in a 2015 book, The Meaning of the Republic. Laïcité is the French word for "secularism".
"In schools, yes, the teaching should be free of religious influence, but in the way they eat, students have every right to eat according to any creed they may choose in school cafeterias," he said. "The food served should recognise on some days the common ground, by serving vegetables, omelets, fruits - and some other days diversity by serving meats, fish and alternatives to them."
In the French press, Sanchez has couched his decision in the context of fighting the "Grand Remplacement," or "great replacement". This is a term introduced by the French polemicist Renaud Camus, whose writing is de rigueur on the far right, which suggests the colonisation of France by Muslims, mostly from former colonies.
As Sanchez told Valeurs Actuelles, a conservative news magazine: "I refuse to assist in the great replacement of pork at the cafeteria."
"There is a population substitution at work in France, a migratory invasion decided by the government - that's a reality," the mayor said. "It imposes a communitarianism we must refuse, because it's based on religion. I recognize everyone's right to worship, to have a religion - but in the private sphere. In the public space this religion should never be imposed."
Pressed about the expansive nativity scene at the entry to the town hall - a religious symbol on the grounds of a facility owned and operated by the secular French state - he insisted that a judge had authorised its presence. Said Sanchez: "It's part of the history of France."
