Work in Greek island European parliament backed (5)
I believe the answer is:
iliad
'work in greek' is the definition.
(Greek epic)
'island european parliament backed' is the wordplay.
'island' becomes 'i'.
'european parliament' becomes 'dail' (Dail Eireann, part of Irish parliament).
'backed' says the letters should be written backwards.
'dail' in reverse letter order is 'liad'.
'i'+'liad'='ILIAD'
(Other definitions for iliad that I've seen before include "Epic poem attributed to Homer" , "Poem by 4 across" , "The -----, Homeric epic" , "Long Homeric poem" , "Epic piece of writing" .)