Officers of the CRS riot police are deployed as lifeguards at beach resorts in July and August each year. In the past they have abandoned their guns, flak jackets and helmets in favour of swimming trunks, sunglasses and T-shirts when taking up the much coveted perch on a lifeguard’s chair.

The officers in charge of beach first-aid centres and their deputies will now carry guns in sand-proof holsters, specially designed for use with beachwear. Bullet-proof vests will be kept near lifeguard posts.

“We will be ready to act if there is an armed attack on a beach,” Nicolas Comte, a police union spokesman, said.

The decision is thought to have been motivated partly by the need to reassure tourists in one of the world's favourite holiday destinations, which has also been hit by a long series of often violent protests against labour reforms.