Pioneering MP Nancy — minister powerless! (5)

I believe the answer is:

astor

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'pioneering mp' is the definition.
(Nancy Astor, first female MP in UK)

I can't explain the remainder of the clue.

(Other definitions for astor that I've seen before include "First female MP" , "female parliamentarian" , "Nancy --, one-time MP" , "Nancy ---, first woman MP" , "Female politician" .)

I've seen this clue in The Times.

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