Still supporting European Commission over the moon (8)
I believe the answer is:
ecstatic
'over the moon' is the definition.
(I've seen this before)
'still supporting european commission' is the wordplay.
'still' becomes 'static' (synonyms).
'supporting' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'european commission' becomes 'EC' (abbreviation).
'static' after 'ec' is 'ECSTATIC'.
(Other definitions for ecstatic that I've seen before include "On cloud nine" , "Blissfully happy" , "Feeling immense joy" , "Cites act, being deliriously happy" , "Full of bliss" .)