Liberal or a Conservative's uplifting song of joy (5)
I believe the answer is:
carol
'song of joy' is the definition.
(I've seen this in another clue)
'liberal or a conservative's uplifting' is the wordplay.
'liberal' becomes 'l' (abbreviation).
'conservative' becomes 'C' (UK political abbreviation).
'uplifting' says the letters should be written backwards.
'l'+'or'+'a'+'c'='lorac'
'lorac' back-to-front is 'CAROL'.
(Other definitions for carol that I've seen before include "Female" , "Joyful song - girl's name" , "Joyful song - woman's name" , "A traditional Christmas song or hymn" , "Christmas ditty" .)