Controversial European given reason to act (7)
I believe the answer is:
emotive
'controversial' is the definition.
(I've seen this before)
'european given reason to act' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'given' means one lot of letters go next to another.
'reason to act' becomes 'motive' (a motive is a reason for doing something).
'e'+'motive'='EMOTIVE'
(Other definitions for emotive that I've seen before include "Causing strong feelings" , "Arousing intense feeling" , "Showing feelings" , "Argumentative" , "Sensitive - controversial" .)