One directly responsible for NHS cuts? (7)

I believe the answer is:

scalpel

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'one' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.

I can't explain the rest of the clue.

Can you help me to learn more?

(Other definitions for scalpel that I've seen before include "Surgical blade" , "Sharp cutting tool" , "sharp knife" , "A surgeon's knife 97)" , "Surgical implement" .)

I've seen this clue in The Sun.

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