Union campaigner messing up gets the bird (8,7)

I believe the answer is:

macaroni penguin

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'up gets the bird' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'union campaigner messing' is the wordplay.
'messing' indicates an anagram.
'union'+'campaigner'='unioncampaigner'
'unioncampaigner' is an anagram of 'MACARONI PENGUIN'.

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I've seen this clue in The Guardian.

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