Take issue with small operation on model (6)
I believe the answer is:
oppose
'take issue' is the definition.
(thesaurus)
'small operation on model' is the wordplay.
'small operation' becomes 'op' (I am not sure about the 'small' bit.**).
'on' means one lot of letters go next to another.
'model' becomes 'pose' ('pose' can be a synonym of 'model').
'op'+'pose'='OPPOSE'
'with' acts as a link.
Can you help me to learn more?
(Other definitions for oppose that I've seen before include "Argue against" , "Resist, contend with" , "match" , "Resist, be hostile to" , "Compete with" .)