It is not just England.I was told by a city employee to stop taking photographs of the Boats in the Public marina a few years ago. When I informed him of my interest in the ducks in said marina, he still told me to pack it up and leave public property. I didn't argue with him, and left politely. I was ticked off enough to enquire with the School police liaison officer the next day. He was incredulous that such an event happened. However, he did state that I did the right thing, as under the law, all public city property is technically owned by the Mayor, and thus they can charge trespassing.
UK is turning into 1984, that's all. http://www.guardian.co.uk/uk/2010/feb/21/photographer-films-anti-terror-arrest