Conservative prerogative (5)
I believe the answer is:
right
I believe this clue is a double definition.
'conservative' is the first definition.
(similar in meaning)
'prerogative' is the second definition.
(a prerogative is a legal right)
(Other definitions for right that I've seen before include "Punch" , "ideal" , "The hand to the east when facing north" , "Girth (anag)" , "Correct; proper" .)