Aura surrounds Conservative, one showing foreknowledge (10)
I believe the answer is:
prescience
'foreknowledge' is the definition.
(prescience is knowledge of things to come)
'aura surrounds conservative one' is the wordplay.
'aura' becomes 'presence' (aura can mean a presence or atmosphere).
'surrounds' is an insertion indicator.
'conservative' becomes 'C' (UK political abbreviation).
'one' becomes 'i' (Roman numeral).
'c'+'i'='ci'
'presence' placed around 'ci' is 'PRESCIENCE'.
'showing' acts as a link.
(Other definitions for prescience that I've seen before include "knowing what will happen in future?" , "Foresight" , "Foreknowledge" .)