Non-verse style I’d worked out and campaigned for (12)
I believe the answer is:
proselytised
'campaigned for' is the definition.
(to proselytise is to promote ideas)
'non-verse style i'd worked out' is the wordplay.
'non-verse' becomes 'prose' (I've seen this before).
'worked out' indicates an anagram.
'style'+'id'='styleid'
'styleid' anagrammed gives 'lytised'.
'prose'+'lytised'='PROSELYTISED'
'and' acts as a link.
(Other definitions for proselytised that I've seen before include "Tried to convert" , "Converted" .)