European country keeping parliamentarian in government (6)
I believe the answer is:
empire
'government' is the definition.
(empire is a kind of government)
'european country keeping parliamentarian' is the wordplay.
'european country' becomes 'eire' (Eire is an example).
'keeping' is an insertion indicator.
'parliamentarian' becomes 'mp'.
'eire' going around 'mp' is 'EMPIRE'.
'in' acts as a link.
(Other definitions for empire that I've seen before include "Jurisdiction" , "Group of states under the control one authority" , "Large organisation run from one point" , "Former British-ruled countries" , "Group of states with a single monarch" .)