Party to invite scorn (8)
I believe the answer is:
contempt
'scorn' is the definition.
('contempt' can be a synonym of 'scorn')
'party to invite' is the wordplay.
'party' becomes 'con' (abbreviation for Conservatives).
'to invite' becomes 'tempt' (tempting is a kind of inviting).
'con'+'tempt'='CONTEMPT'
(Other definitions for contempt that I've seen before include "Open disrespect, to a court, say" , "Beneath this is despicable" , "Feeling of disdain, perhaps of court" , "Scornful feeling" , "Offence of disrespect in court" .)