Try politician in North West town (6)
I believe the answer is:
sample
'try' is the definition.
(synonyms)
'politician in north west town' is the wordplay.
'politician' becomes 'mp' (Member of Parliament).
'in' means one lot of letters goes inside another.
'north west town' becomes 'sale' (Greater Manchester town).
'mp' inserted into 'sale' is 'SAMPLE'.
(Other definitions for sample that I've seen before include "Specimen, try out" , "Take" , "Taste(r)" , "piece to try" , "Test the specimen" .)