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 "United Kingdom general election, 1955"): It resulted in a substantially increased majority of 60 for the Conservative government under new leader and prime minister Sir Anthony Eden against the Labour Party, then in their twentieth year of leadership by Clement Attlee.
Relevant evidence: Yes