Raven30,
There was what appeared to be a 'Purple Flight' last Sunday. If it wasn't a Royal Flight, then there were certainly plenty of temporary upgrades to Class A airspace around the Farnborough, Odiham and Lyneham areas.
I found out about it by calling 0500 354802.
It's worth making time to call this number before every flight.
HTH,
B73
Edited to add: Ooops, sorry Mariner9. Just realised that I've repeated what you suggested.