Having taken power will continue, you suppose (7)
I believe the answer is:
presume
'suppose' is the definition.
(thesaurus)
'having taken power will continue you' is the wordplay.
I cannot quite understand how this works, but
'power' could be 'p' and 'p' is found in the answer.
'continue' could be 'resume' (resuming is a kind of continuing) and 'resume' is present in the answer.
No letters remain.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for presume that I've seen before include "Suppose without proof" , "Surmise" , "Suppose; take liberties" , "Take to be the case" , "Believe" .)