Refuse to accept former company representative having authority (8)
I believe the answer is:
official
'representative having authority' is the definition.
'refuse to accept former company' is the wordplay.
'refuse' becomes 'offal' (I've seen this in other clues).
'to accept' means one lot of letters goes inside another.
'former company' becomes 'ici' (Imperial Chemical Industries).
'offal' placed around 'ici' is 'OFFICIAL'.
(Other definitions for official that I've seen before include "Proper" , "Public employee" , "Certified" , "One is in a position of authority" , "It's no rumour - he's in charge" .)