So Alton Towers has banned embarrassingly titchy swimming trunks at its water park. But spare a thought for France, where the opposite is true: local authorities regularly force men to ditch their Bermudas and parade in skin-tight budgie-smugglers for the greater public good.

In French public pools, from the racing lanes of Paris to the open-air lidos and water parks of the south, anything bigger than Speedos is banned and you must hoist yourself into a posing pouch as a civic requirement. French changing rooms are littered with the broken dreams of prudish males abroad who thought they could sneak in a few lengths without showing their contours.

One Paris-based Irish journalist recalls how he attempted some early-morning back-stroke in a pair of standard Marks & Spencer navy swim shorts that came "about halfway down my thighs". As he lowered himself into the shallow end, the pool attendant screamed that his oversized attire was outlawed. "I said they were being ridiculous and glided into the middle of the pool. A lifeguard jumped into the water after me, three other attendants fetched a big hook for fishing out drowning people and hauled me in. I had to come back in an unbelievably skimpy pair that were somehow acceptable, but bloody uncomfortable for me and anyone who had to look at them."

Why the enforced parading of Frenchmen's bulges? "Hygiene," says Emmanuel Dormois, a head pool attendant in Paris's 11th arrondissement. "Small, tight trunks can only be used for swimming. Bermudas or bigger swimming shorts can be worn elsewhere all day, so could bring in sand, dust or other matter, disturbing the water quality. By banning them outright, we're not forced to stand there measuring what can be defined as swimming shorts. I accept that some men feel very ill at ease wearing small trunks, but others don't mind."

Similar reports of enforced Speedos come from traumatised English visitors to a Belgian water park where bigger swimming shorts were also banned.

Yet on the comparative freedom of French beaches men's crack-splitting tangas and tight nylon slips have gone out of fashion. The smallest tasteful covering is what French stylists call the "boxer" trunk, tight, Daniel Craig-style mini-shorts that look less like ladies' knickers. Not that public pool rules are never challenged. A feminist group has staged topless protests for the right of women to wear only bikini bottoms in line with men. Others argue that if bald men have to wear swimming hats how come others don't have to shave off their beards? And so the debate continues.