I know from "reliable sources" that CAA is concerned about the safety record of ex-mils, which is poor. This is identified primarily as being down to a combination of...
- Maintenance schedules need to be appropriate to civil operation, and it's often difficult to know what should be put together.
- A lot of these aircraft are being flown limited hours, much of which is airshows or associated practice. This is a high-risk operating schedule.
- Source and quality of spares can be an increasing problem.
In addition, there's a general concern over the fact that ex-mils aren't allowed to operate in IMC. The consensus amonst operators is that an aircraft like a Hunter transiting across the country is far safer punching up through cloud in IMC and transiting VFR on-top, than mucking about at 250-400 knots at relatively low level amongst all the GA traffic.
I believe that they are living with it because everybody wants to see these beasts continue to fly, and also because it's perceived that virtually anybody getting into an aircraft in this category is highly experienced, usually ex-military, and therefore well equipped to judge the risks that they are undertaking for themselves - not a view (rightly in my opinion) that CAA takes with CofA aeroplanes.
G