Legal figure hasn't finished with politician (9)
I believe the answer is:
statutory
'legal' is the definition.
(similar in meaning)
'figure hasn't finished with politician' is the wordplay.
'figure' becomes 'statue' (statue is a kind of figure).
'hasn't finished' means to remove the last letter.
'with' is a charade indicator (letters next to each other).
'politician' becomes 'tory' (term for a Conservative Party politician).
'statue' with its last letter taken off is 'statu'.
'statu'+'tory'='STATUTORY'
(Other definitions for statutory that I've seen before include "Of written law as to a trusty" , "Relating to written law" , "In accordance with written law" , "According to law" , "Prescribed or authorised by law" .)