Lackey follows party in government (8)
I believe the answer is:
dominion
'government' is the definition.
(I've seen this before)
'lackey follows party' is the wordplay.
'lackey' becomes 'minion' (both can mean an assistant or henchperson).
'follows' is a charade indicator (letters next to each other).
'party' becomes 'do' (do is a kind of party).
'minion' after 'do' is 'DOMINION'.
'in' acts as a link.
(Other definitions for dominion that I've seen before include "Authority to rule over and control people" , "power" , "Territorial possession controlled by a ruling state" , "Realm" , "Area of control" .)