Fast-talking Nationalist's plan (7)
I believe the answer is:
pattern
'plan' is the definition.
(pattern is a kind of plan)
'fast-talking nationalist's' is the wordplay.
'fast-talking' becomes 'patter'.
'nationalist' becomes 'n' (abbreviation in politics).
'patter'+'n'='PATTERN'
(Other definitions for pattern that I've seen before include "Design for copying" , "Repeated decorative design" , "Sewing plan" , "Stencil" , "style" .)