Refuse permission in suave tones (4)
I believe the answer is:
veto
'refuse permission' is the definition.
(I've seen this before)
'in suave tones' is the wordplay.
'in' says the answer is hidden in the clue.
'VETO' is hidden in the letters of 'suave tones'.
(Other definitions for veto that I've seen before include "Reject - vote (anag)" , "Right to reject a proposal" , "Disallow" , "black ball" , "Refusal to assent" .)