Models behind work counters (7)
I believe the answer is:
opposes
'counters' is the definition.
(I've seen this before)
'models behind work' is the wordplay.
'models' becomes 'poses' ('pose' can be a synonym of 'model').
'behind' is a charade indicator (letters next to each other).
'work' becomes 'op' (short for opus).
'poses' put after 'op' is 'OPPOSES'.
(Other definitions for opposes that I've seen before include "Strongly disapproves" , "Counters" , "Stands against" , "Disagrees with and attempts to prevent" , "Goes against" .)