Sarcasm aside for a moment, an NFZ could be imposed by a force of Tornados/Typhoons?, AWACS and presumably some AAR support. From Malta its about 200nm to Tripoli, assuming Malta could be used. Assuming the political will was there - big question I know -and talking purely in practical terms, is Britain no longer capable of providing such a force? What would be the obstacles in the way of detaching the necessary number of suitable aircraft to carry out such duties?
Suggestion of basing Typhoons at RAF Akrotiri here. A fair transit time with an ~1000 mile distance.
RAF Typhoons Could Enforce Libya No-Fly Zone - Yahoo! News UK