...Conservative leader getting brighter staff (7)
I believe the answer is:
crosier
'staff' is the definition.
(crosier is a kind of staff)
'conservative leader getting brighter' is the wordplay.
'leader' indicates taking the first letters.
'getting' says to put letters next to each other.
'brighter' becomes 'rosier' (I've seen this before).
The first letter of 'conservative' is 'c'.
'c'+'rosier'='CROSIER'
(Other definitions for crosier that I've seen before include "Staff carried by a bishop" , "one's hooked!" , "A bishop's staff as symbol of office" , "Bishop's crook" , "Ecclesiastical staff" .)