Left exploit outside faction (8)

I believe the answer is:

decamped

'left' is the definition.
(decamping is a kind of leaving)

'exploit outside faction' is the wordplay.
'exploit' becomes 'deed' (both can mean a feat or escapade).
'outside' means one lot of letters goes inside another.
'faction' becomes 'camp' (both can mean a side in an argument).
'deed' going around 'camp' is 'DECAMPED'.

(Another definition for decamped that I've seen is " Went away suddenly or secretly".)

I've seen this clue in The Irish Times.

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