Apply to become political leader of advertising department! (10)
I believe the answer is:
administer
'apply' is the definition.
(administering is a kind of applying)
'political leader of advertising department' is the wordplay.
I cannot really see how this works, but
'leader' could be 'minister' (minister is a kind of leader) and 'minister' is found within the answer.
'advertising' could be 'ad' (synonyms) and 'ad' is found in the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'to become' acts as a link.
Can you help me to learn more?
(Other definitions for administer that I've seen before include "Govern" , "Oversee" , "control" , "man?" , "conduct" .)