Town in Kent remains in favour of Duke (7)
I believe the answer is:
ashford
'town in kent' is the definition.
(I've seen this before)
'remains in favour of duke' is the wordplay.
'remains' becomes 'ash' (remains of a fire).
'in favour of' becomes 'for' (being for a particular cause).
'duke' becomes 'd' (abbreviation).
'ash'+'for'+'d'='ASHFORD'
(Other definitions for ashford that I've seen before include "Kent town with rail link to Paris" , "Town in Kent with international rail station" , "seen en route to the Channel Tunnel" , "Daisy" .)