"and all labour voters informed their local labour councillors that their support/vote was being withdrawn."

Much as I support the cause, being one of the players affected by Sam Smith's ban, I think that this would be an extreme reaction, even if it were actually feasible to do. It could just be that labour councillors are the more helpful on other issues such as social services, local transport provision, education and so on. Are we saying that playing music is MORE important than those things and we should withdraw our support from the coucillors because of their party's contrary position on that? I don't think so, let's get some perspective.