PARIS — A heated debate over France’s values reignited across the country this week, the latest fight in a culture war that has raged for years in universities, the halls of government and even on the beach.

This time, it started with a mother wearing a hijab on a school trip.

Veils and head scarves are political and social lightning rods in France, touching on issues so sensitive — secularism, feminism and the integration of Muslims — that they seem to inspire anger wherever they appear. Although the mother broke no laws by wearing the garment, which does not cover the face, she enraged far-right members of the local assembly that the schoolchildren were visiting.

During the visit last week, in the central city of Dijon, one of the politicians, Julien Odoul, asked that the woman uncover herself.

“Madame has ample time to wear her veil at home, on the street, but not here, not today,” he said, citing France’s values of secularism, known as laïcité.