Labour with scanty reform for police (12)
I believe the answer is:
constabulary
'police' is the definition.
('constabulary' can be a synonym of 'police')
'labour with scanty reform' is the wordplay.
'with' means one lot of letters go next to another.
'reform' indicates anagramming the letters.
'labour' after 'scanty' is 'scantylabour'.
'scantylabour' anagrammed gives 'CONSTABULARY'.
'for' is the link.
(Other definitions for constabulary that I've seen before include "Police force or station" , "14 6 or 2" .)