They do wrong to stop interrupting proposals (9)
I believe the answer is:
offenders
'they do wrong' is the definition.
The definition suggests an adverb but the answer is not.
'stop interrupting proposals' is the wordplay.
'stop' becomes 'end' (synonyms).
'interrupting' is an insertion indicator.
'proposals' becomes 'offers' (I've seen this in another clue).
'end' placed within 'offers' is 'OFFENDERS'.
'to' is the link.
Can you help me to learn more?
(Other definitions for offenders that I've seen before include "Criminals" , "Perhaps thieves" , "Miscreants" , "Lawbreakers" , "Wrongdoers" .)