Wary that man Miliband fleeces unsuspecting Labour leaders (7)
I believe the answer is:
heedful
'wary' is the definition.
(I've seen this before)
'man miliband fleeces unsuspecting labour leaders' is the wordplay.
'man' becomes 'he' (he refers to a man).
'miliband' becomes 'ed' (politician Ed Miliband).
'leaders' says to take the initial letters.
The first letters of 'fleeces unsuspecting labour' is 'ful'.
'he'+'ed'+'ful'='HEEDFUL'
'that' is the link.
(Other definitions for heedful that I've seen before include "Wary" , "Attentive - circumspect" , "Paying careful attention" , "Cautious" , "Attentive, listening carefully" .)