Revolting to-do in France about European Union (13)
I believe the answer is:
confederation
'union' is the definition.
(confederation is a kind of union)
'revolting to-do in france about european' is the subsidiary indication.
'revolting' is an anagram indicator.
'about' is an insertion indicator.
'european' becomes 'e' (abbreviation e.g. EU).
'to'+'do'+'in'+'france'='todoinfrance'
'todoinfrance' with letters rearranged gives 'confedration'.
'confedration' placed around 'e' is 'confederation'.
(Other definitions for confederation that I've seen before include "Alliance of several parties" , "Alliance of states" , "Union (of states)" , "Loose alliance of political units" , "Group of allies" .)