Short finals,
Yes, I am aware of our 'spotter' movement.
As is the case with most posters on this and other boards, I do not have 'hard evidence' regarding RAF jets movements in our airspace (and airports) but am merely relaying what I have read in the Irish media (and to some degree, on IMO).
E.g. It was mentioned on IMO that the RAF have 2 x F3's on standby at RAF Colingsby (?) for the purpose of intercepting suspect aircraft in Irish airspace. These aircraft, apparently, can be over the west coast of Ireland within minutes of an alert.
I suspect that RAF jets do not patrol our airspace on a regular basis, but perform the occassional overflight, etc to familarize themselves with our terrain - with our govts (quiet!) consent ofcourse.