Profligate MP has issues about priority (8)
I believe the answer is:
emphasis
'priority' is the definition.
(thesaurus)
'profligate mp has issues about' is the wordplay.
'about' says the answer is hidden in the clue.
'EMPHASIS' is hidden in the letters of 'profligate mp has issues'.
(Other definitions for emphasis that I've seen before include "Stress given to a word" , "Stress, accent" , "Stress or significance" , "Stress, accentuation" , "Stress - misshape (anag)" .)