Oblige Pimlico MP, electioneering, just a bit (6)
I believe the answer is:
compel
'oblige' is the definition.
('compel' can be a synonym of 'oblige')
'pimlico mp electioneering just a bit' is the wordplay.
'a bit' says the answer is hidden in the clue (the answer is formed by a bit of the clue).
'COMPEL' is hidden within 'pimlico mp electioneering just'.
(Other definitions for compel that I've seen before include "Use force or influence to make something happen" , "Urge on, force" , "Coerce, force to obey" , "Use force, oblige" , "'Force, oblige (6)'" .)