Question:  A British Conservative politician who served three periods as what, that had  a substantially increased majority of 60 for the Conservative government against the Labour Party?
Sentence (from "Clement Attlee"): However, he was narrowly defeated by the Conservatives under the leadership of Winston Churchill; despite winning the most votes of any political party in any general election in British political history until the Conservative Party's fourth consecutive victory in 1992.
Relevant evidence: No