Further to my last post there is anecdotal suggestion that the UK Government is considering legislation that would make significantly restrict the taking of street photography and documentary photography (whatever that means exactly). There are however no official government sources that have alluded to such legislation as far as I'm aware but given some of the authoritarian laws we've had introduced by this government it would not be much of a surprise if it was brought through.
There is a petition against this at
Petition to: Stop proposed restrictions regarding photography in public places.
I am not certain if such a law would be UK-Wide or only apply in England, perhaps someone more knowledgeable in legal matters can clarify for us.