Succeeded, Conservative with effective lying (12)
I believe the answer is:
storytelling
'lying' is the definition.
'succeeded conservative with effective' is the wordplay.
'succeeded' becomes 's' (genealogical abbreviation).
'conservative' becomes 'tory' (informal term for a Conservative Party member).
'with' is a charade indicator (letters next to each other).
'effective' becomes 'telling' (synonyms).
's'+'tory'+'telling'='STORYTELLING'
(Other definitions for storytelling that I've seen before include "Narration" , "Narrating tales" .)