Clue: Stalwart Tory earl shunned by Camilla and her old man, mistakenly (6,9)
Answer: HAROLD MACMILLAN
Explanation: Definition: Stalwart Tory
Harold Macmillan was a Tory PM and became the Earl of Stockton
 *Edit thanks to Lord Jim: (Camilla her old man)* minus an 'E' for "earl"*
 ~~(Camilla and her old man)* minus the letters from "earl"~~