Firedog regularly fanned vitriol before end of election (7)
I believe the answer is:
andiron
'firedog' is the definition.
(synonyms)
'regularly fanned vitriol before end of election' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'before' is a charade indicator (letters next to each other).
'end of' suggests the final letters.
The last letter of 'election' is 'n'.
'fanned'+'vitriol'='fannedvitriol'
The alternate letters of 'fannedvitriol' are 'andiro'.
'andiro'+'n'='ANDIRON'
(Other definitions for andiron that I've seen before include "Firedog -- Odin ran (anag)" , "Stand by the fire" , "Firedog found on drain" , "Logs support" , "One supports burning wood" .)