Not neutral on all occasions (5)

I believe the answer is:

never

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'not' is the definition.
(thesaurus)

I can't explain the remainder of the clue.

(Other definitions for never that I've seen before include "Strong negative" , "On no occasion" , "At no time in the past or future" , "when pigs fly" , "Surely not" .)

I've seen this clue in the Evening Standard.

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