Novelist and politician in conversation (6)
I believe the answer is:
greene
'novelist' is the definition.
(Graham Greene)
'politician in conversation' is the wordplay.
'politician' becomes 'green' (eg member of the Green Party).
'in conversation' indicates a 'sounds like' (homophone) clue.
'green' is a homophone of 'GREENE'.
'and' is the link.
(Other definitions for greene that I've seen before include "Graham -, English novelist" , "Graham -, English author (Brighton Rock)" , "Graham -, twentieth century English author" , "writer" , "Graham --, Eng. author" .)