Fellow with UK country relations is a model (8)
I believe the answer is:
mannikin
'a model' is the definition.
'fellow with uk country relations' is the wordplay.
'fellow with' becomes 'man' (I've seen this in other clues).
'uk country' becomes 'ni' (short for Northern Ireland, a country of the UK).
'relations' becomes 'kin' (I've seen this before).
'man'+'ni'+'kin'='MANNIKIN'
'is' is the link.
(Other definitions for mannikin that I've seen before include "Anatomical model - dwarf - child" , "minor fellow" , "Clothes dummy" , "Little chap" .)