Having in government won over first (6)
I believe the answer is:
owning
'having' is the definition.
('own' can be a synonym of 'have')
'in government won over first' is the wordplay.
'government' becomes 'g' (**).
'over' indicates an anagram.
'first' says to put letters next to each other.
'won' with letters rearranged gives 'own'.
'in'+'g'='ing'
'ing' after 'own' is 'OWNING'.
(Other definitions for owning that I've seen before include "Conceding - possession" , "Possesing" , "Possessing" , "Admitting" , "Being in possession or confessing" .)