One taking dive breaks GNP rule (7)

I believe the answer is:

plunger

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'one taking dive' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.

'breaks gnp rule' is the wordplay.
'breaks' indicates an anagram.
'gnp'+'rule'='gnprule'
'gnprule' is an anagram of 'PLUNGER'.

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(Other definitions for plunger that I've seen before include "Sink unblocker" , "Device for clearing blocked drains" , "Rubber pipe unblocker" , "Drain unblocker" , "diver" .)

I've seen this clue in The Sun.

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