Conservative MP has issue concealing accent (8)
I believe the answer is:
emphasis
'accent' is the definition.
('emphasis' can be a synonym of 'accent')
'conservative mp has issue concealing' is the wordplay.
'concealing' indicates a hidden word.
'EMPHASIS' is hidden in the letters of 'conservative mp has issue'.
(Other definitions for emphasis that I've seen before include "Accentutation" , "Weight" , "Stress, accentuation" , "Stress - misshape (anag)" , "Stress or significance" .)