Person returned to office after business school (4)

I believe the answer is:

comp

'school' is the definition.
(short for comprehensive school)

'person returned to office after business' is the wordplay.
'person returned to office' becomes 'mp' (Member of Parliament, someone in elected office).
'after' is a charade indicator (letters next to each other).
'business' becomes 'co'.
'mp' put after 'co' is 'COMP'.

I've seen this clue in The Times.

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