Desperate model, extremely small (4-6)

I believe the answer is:

last-minute

'desperate' is the definition.
(last-minute efforts might be desperate)

'model extremely small' is the wordplay.
'model' becomes 'last' (model used by a shoemaker).
'extremely small' becomes 'minute' (I've seen this before).
'last'+'minute'='LAST-MINUTE'

(Other definitions for last-minute that I've seen before include "Eleventh hour" , "Eleventh-hour" , "very late" , "Done at the latest possible moment" , "Done at the final moment" .)

I've seen this clue in The Guardian.

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