LTP,
I too have a very good idea of the airfield involved given the description by the OP. (Release level being the biggest give away).
Now once again, if I guessed your destination right, I would invariably have been offering you to the large military radar unit located just on your right as you leave CAS.
In this case you would have been wrong to do so. It is obvious that the destination airfield had radar manned (they do not always), therefore the procedure, as per MATS part 2, is to hand the aircraft to them. In the event of this particular destination airfield having radar unmanned (they still have some staffing issues), then the London controller is to first offer the traffic to the military airfield, but they often refuse to work it if they have nothing to effect.
BTW, they often refuse to work it even if they have traffic to effect if their traffic is on a Basic or Traffic service, thinking quite correctly, but totally unhelpfully, that as their own traffic is not expecting avoidance vectors, it is perfectly acceptable to have another aircraft, on an IFR flight plan, fly towards it.
The real issue is the lack of CAS for an airfield that wants to be a bigger player in commercial aviation (something that is echoed by many airfields)