France is going through one of its periodic bouts of "secularitis" - that disease of the national soul whose symptom is loud and prolonged agonising over the encroachments of religion.

This time the issue is school meals - and specifically the question of whether town authorities should be obliged to offer Muslim children an alternative to pork, whenever pork appears on the menu.

In some countries, that might seem a no-brainer. "Why not?" would be a more likely interrogation.

The latest row has erupted over a decision by the Burgundy town of Chalon-sur-Saone to end the practice of so-called "substitute meals".

For 30 years, the town's schools - like most schools in France - have provided an alternative menu for Muslim (and the far fewer Jewish) children on the occasional days when the meat part of the lunch is from the pig.

But abruptly last month - at the start of this school year - the centre-right mayor Gilles Platret decided that this was to end.

The reason he gives is a sound invocation of the country's long-standing secular values. If children do not want to eat pork, says Platret, then they can fill up on starters and vegetables; they can arrange their own packed lunches; or they can go home.

If parents are really concerned, they can send their children to Muslim schools in the private sector. He also notes that even when pork is not on the menu, many Muslim children are under instructions from parents not to touch meat of any kind because in French schools it is generally not halal.

However, the opposing view holds that what Platret has done at Chalon-sur-Saone is unnecessary, inflammatory and politically motivated.

The Socialist government accuses the mayor of "talking Muslim children hostage".

Removing the possibility of a "non-confessional" menu - according to Education Minister Najat Vallaud-Belkacem - "is tantamount to barring access to the canteen" because many Muslim children will be told by their parents to stay away.