Acted in unison to scupper public attacks (13)

I believe the answer is:

denunciations

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'public attacks' is the definition.
The answer and definition can be both related to communication as well as being plural nouns.
Perhaps they are linked in a way I don't understand?

'acted in unison to scupper' is the wordplay.
'to scupper' indicates an anagram (I've seen 'scuppered' mean this ('scuppered' can mean wrecked)).
'acted'+'in'+'unison'='actedinunison'
'actedinunison' is an anagram of 'DENUNCIATIONS'.

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I've seen this clue in The Times.

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