Its engine? whistled rather than the usual roar. Has the Mirage 2000 been eliminated from the enquiry?
If it whistled then it wasnt a Mirage 2000, they fly over here all the time and they definitely roar (only one big F-off engine!) - whatever the altitude!! (favorite trick is to blast through the overhead of my local aeroclub at 1000-1500ft when cutting the corner between the two restricted areas close by...)
it had a small delta wing with stubby nose, looked like a flying shuttlecock in outline.
AlfaJet ?
Even the RAF have some Alfajets.....
Regards, SD..
PS. for those thinking "Skyhawk, where from?" There used to be Skyhawks based at Cazeaux, just down the road from here, the first few times I definitely ID'ed them as such I thought I was going nuts too...not sure if they are still there as I havent seen them for a while.