In 1950 the Cold War turned hot in Korea, the threat of atomic annihilation hovered menacingly and the spectre of another world war haunted Europe. The establishment of the World Peace Council that year was one response to these fears. In November 1950 the Council decided to hold a World Peace Congress in Sheffield. The British Labour government sabotaged this Congress and forced it to shift to Warsaw. This article analyses this event which, to date, has received no scholarly attention. It argues that the attitudes and actions of the protagonists were a microcosm of the Cold War in that each side, East and West, saw the Congress as an opportunity to achieve moral authority, political leverage and strategic advantage over the other. The article also highlights the role of the state in controlling major political events during the Cold War.