Follow party heading for government (3)
I believe the answer is:
dog
'follow' is the definition.
(dog can mean to follow or torment)
'party heading for government' is the wordplay.
'party' becomes 'do' (do can informally mean a party).
'heading for' suggests taking the first letters.
The first letter of 'government' is 'g'.
'do'+'g'='DOG'
(Other definitions for dog that I've seen before include "'You cannot teach an old ... new tricks'" , "boxer?" , "Contemptible man" , "Follow closely; animal" , "Canine animal" .)