UK - Mayor of London Boris Johnson

...........................And not only to have more public conveniences, but in an age when bottled water has become taboo and when alcohol has been banned on public transport, to have a new crop of drinking fountains across the city and I don’t think I am betraying confidences if I say that if we can make sure there isn’t too much fluoride in the water we can have the support that vital architecture critic of the Prince of Wales. ..............................

What did he mean - does Charles oppose fluoridation?