Follow writer, but not Penny Townsend, say (5)
I believe the answer is:
ensue
'follow' is the definition.
(ensue can mean to follow or happen as a result)
'writer but not penny townsend say' is the wordplay.
'writer' becomes 'pen' (something which writes).
'but not' suggests deleting specific letters.
'penny' becomes 'p' (short for pence).
'townsend say' becomes 'Sue' (Sue Townsend was a British novelist).
'pen' with 'p' taken out is 'en'.
'en'+'sue'='ENSUE'
(Other definitions for ensue that I've seen before include "Cultivate plants/vegetables" , "Arise" , "Happen - to come later" , "Proceed" , "Happen or come about as consequence" .)