Be candidate, popular, as deputy (5-2)

I believe the answer is:

stand-in

'deputy' is the definition.
(thesaurus)

'be candidate popular' is the wordplay.
'be candidate' becomes 'stand'.
'popular' becomes 'in'.
'stand'+'in'='STAND-IN'

'as' acts as a link.

(Another definition for stand-in that I've seen is " Substitute".)

I've seen this clue in The Times.

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