Swindled Conservative departs furious (6)
I believe the answer is:
heated
'furious' is the definition.
(I've seen this before)
'swindled conservative departs' is the wordplay.
'swindled' becomes 'cheated'.
'conservative' becomes 'C' (UK political abbreviation).
'departs' indicates named letters should be taken away.
'cheated' with 'c' taken away is 'HEATED'.
(Other definitions for heated that I've seen before include "Brief extract" , "Fired-up" , "Baked; angry" , "Made warm" , "Angry or warmed" .)