Offer by Conservative candidate (9)
I believe the answer is:
contender
'candidate' is the definition.
(I've seen this before)
'offer by conservative' is the wordplay.
'offer' becomes 'tender' (tender offer is a kind of offer).
'by' says to put letters next to each other.
'conservative' becomes 'con' (I've seen this in other clues).
'tender' put after 'con' is 'CONTENDER'.
(Other definitions for contender that I've seen before include "Competitor, challenger" , "One striving" , "One fighting others (for something)" , "Struggler in rivalry" , "Trend once (anag.)" .)