I don't know if it is satire. I would not doubt it legitimacy. It is England - which is bloody cold AND many Brits take package vacations to Spain where toplessness on the beach is common. Since they are not showing up in Spain these days (as noted in a recent NPR report), why not stay home and release the twins, as the mums would say? The Canary Islands, where I have visited a couple times in the past 2 years, is chocka with Brits and Germans; however, it is now reporting a 30% unemployment. I rented a pad with kitchen and right on the beach sea view balcony from a naturist British couple last time (less than $50 per night). Food establishments were unusually quiet.
What I remember reading is how nudism is increasing faster with Republicans than with Democrats. Must be the family values aspect...