Alan,
That's why I'm suggesting merely a dedicated frequency and blind calls, because it doesn't take staff and money. All it takes is someone to make the decision.
Is there anyone reading this who could do it?
QDM3, non-compulsory blind calls, OK? Just the option, for those of us who'd like to tell the world where we are, and hopefully hear who else is around, in a crowded area. It works for helicopters in LA - and there are really a lot of them. Why not for GA around London?