A foreign couple working on the paper not in The Union (10)
I believe the answer is:
unattached
'not in the union' is the definition.
I can't tell whether this defines the answer.
'a foreign couple working on the paper' is the wordplay.
'a foreign' becomes 'un' ('a' translated into French).
'couple' becomes 'attach' (I've seen this before).
'working on the paper' becomes 'ed' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'un'+'attach'+'ed'='UNATTACHED'
Can you help me to learn more?
(Other definitions for unattached that I've seen before include "Not belonging" , "Not married" , "Not joined" , "Single" , "independent" .)