Conservative working with despicable person, socialist agreed (9)
I believe the answer is:
concurred
'agreed' is the definition.
('concur' can be a synonym of 'agree')
'conservative working with despicable person socialist' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'working' becomes 'on' (e.g. a machine is working or on).
'with' means one lot of letters go next to another.
'despicable person' becomes 'cur' (I've seen this in another clue).
'socialist' becomes 'red' (red can informally mean a socialist).
'c'+'on'+'cur'+'red'='CONCURRED'
(Other definitions for concurred that I've seen before include "Acquiesced" , "Agreed" .)