Having just seen the thread for the first time I'm slightly surprised that no one actually answered the OP's question. The reason why there won't be another Lightning flight in the UK is simply that it has ALWAYS been CAA policy not to allow civil registration of former military jets that are capable of supersonic straight & level flight. I think there may have been a very few exceptions for one-of ferrying flights out of the UK, but these were subject to extraordinary scrutiny and were heavily NOTAM'd.
Ads for the other comments - I really do love the idea that any civilian MU would do more intensive maintenance that front line squadrons. Some people cleary haven't the first clue on what is involved in keeping a 2nd generation jet like a lightning in the air. Best data I can find in the files here would be a first-line maintenance man-hours per flying hour number (preventive and corrective) of 112hrs, but that's based on a fleet of several squadrons and a flying rate of 210hrs/yr per aircraft (against a target of 305hrs/yr/AC). And that's only the 1st line mainteance man-hours - it excludes all the supporting bays and what we would now call "depth" mainteance. Of course you could strike out the maintenance associated with the radar, guns, missile systems and refuelling probes because these would never be used in a disply aircraft. But I'm under the impression that most of the mainteance burden of the Lightning was flight systems (flight controls, engine, undercarriage and instruments) plus the on-going aircraft husbandry (zonals and fatigue-driven SIs) so that's probably not as big a saving as it sounds.
But a display aircraft would do, what, 50-100hrs/yr? Much of that 1st line stuff would still occur at the same rate, so the maintenance manhrs per flying hour number would be 2-4 times higher. Lets make some generous assumptions - lets assume 100hrs/yr of display and practice/test flying. Let's assume that the maintenance requirement remains only 112hrs/flying hr, and that the additional maintenance hours of depth and bay maintenance (plus the increased rate per hour due to the lower utilisation) are offset by the lack of "military features" maintenance (that's unlikely, but what the heck). That would result in a an annual maintenance manpower requirement of 11,000 hours (six people, full time). That works out to over a million quid a year in maintenance man-hours alone, never mind parts, fuel, consumables, admin etc. Could the aeroplane even hope to earn that back in display fees?
I think not...
PDR