Conservative forte at end of day unclear (6)
I believe the answer is:
cloudy
'unclear' is the definition.
(thesaurus)
'conservative forte at end of day' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'forte' becomes 'loud' (similar in meaning).
'at end of' suggests the final letters.
The final letter of 'day' is 'y'.
'c'+'loud'+'y'='CLOUDY'
(Other definitions for cloudy that I've seen before include "Not transparent" , "'Overcast, nebulous (6)'" , "(Of a liquid) not clear" , "Murky or nebulous" , "Obscure" .)