EU retaining money raised for ally (5)
I believe the answer is:
unite
'ally' is the definition.
(I've seen this before)
'eu retaining money raised' is the wordplay.
'retaining' means one lot of letters goes inside another.
'money' becomes 'tin' (I've seen this before).
'raised' says the letters should be written in reverse.
'eu' enclosing 'tin' is 'etinu'.
'etinu' reversed gives 'UNITE'.
'for' is the link.
(Other definitions for unite that I've seen before include "Get together" , "Group of workers" , "Gather together as one" , "Join together, become one" , "Pull together" .)