Come forward, raising heartless Punch and Judy (4,2)

I believe the answer is:

step up

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'come forward' is the definition.
(synonyms)

I cannot understand how the rest of the clue works.

(Other definitions for step up that I've seen before include "Advancement (on a ladder or career)" , "- Bezukhov (War and Peace)" , "Raise by stages" , "Increase as with pace - or ascend stair?" , "Come forward" .)

I've seen this clue in The Hindu.

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