I have fully researched a guide to busking law in the uk as part of my degree in popular music.
It has been endorsed officially by wakefield police, as a national guide.
I have had numerous apologies since challenging different organisations and they all promise never to do it again.

I find that you often have to explain the law to the police and council officials and then they never bother you again.
You can read the guide here

Busking and UK Law