Suggest work in writing (7)
I believe the answer is:
propose
'suggest' is the definition.
('propose' can be a synonym of 'suggest')
'work in writing' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'in' indicates putting letters inside.
'writing' becomes 'prose' (I've seen this in other clues).
'op' inserted inside 'prose' is 'PROPOSE'.
(Other definitions for propose that I've seen before include "Offer for consideration" , "table" , "Intend" , "advance" , "Tender" .)