"Not new, but making a comeback," one continued (4,2)

I believe the answer is:

went on

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'one continued' is the definition.
(I've seen this in another clue)

'not new but making a comeback' is the wordplay.
'new' becomes 'n' (abbreviation as in New Testament NT).
'but' becomes 'ew' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'making a comeback' is a reversal indicator.
'not'+'n'+'ew'='notnew'
'notnew' written backwards gives 'WENT ON'.

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(Another definition for went on that I've seen is " Did rabbit".)

I've seen this clue in the Evening Standard.

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