I think there was a court case in the last year or two where after 10 years of losing it initially the police still declined an applicant. Pretty sure it went to court and the Judge was pretty clear he should get a licence back. In fact I think the judge pretty much rodgered the Police over their attitude if I remember.
In the first instance I'd go talk to the local AO, if he still says no then I'd assume you need a lawyer which will cost a few bob, but you'd might well get it back.
Bookmarks