Controversial European cause (7)
I believe the answer is:
emotive
'controversial' is the definition.
(I've seen this before)
'european cause' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'cause' becomes 'motive' (**).
'e'+'motive'='EMOTIVE'
(Other definitions for emotive that I've seen before include "able to get going" , "Arousing strong feeling" , "Affecting, moving" , "arousing passion" , "Arousing strong feelings" .)