Provide objective Brussels promoted (5)
I believe the answer is:
endue
'provide' is the definition.
(I've seen this in another clue)
'objective brussels promoted' is the wordplay.
'objective' becomes 'end' (both can mean a purpose).
'brussels' becomes 'EU' (European Parliament is based in Brussels).
'promoted' says the letters should be written in reverse (going up, in a down clue).
'eu' back-to-front is 'ue'.
'end'+'ue'='ENDUE'
(Other definitions for endue that I've seen before include "Invest - provide" , "Furnish" , "Endow (poetic)" , "Put on clothes" , "Invest (something) with a quality or ability" .)