Resist work with model (6)
I believe the answer is:
oppose
'resist' is the definition.
(I know that resist is a more specific form of the action oppose)
'work with model' is the wordplay.
'work' becomes 'op' (common abbreviation for 'opus').
'with' is a charade indicator (letters next to each other).
'model' becomes 'pose' (model can mean to pose).
'op'+'pose'='OPPOSE'
(Other definitions for oppose that I've seen before include "Take stand against, resist" , "Obstruct, resist" , "Resist, go against" , "Refute - confront" , "Resist, contend with" .)