Which political party did Winston Churchill lead as Prime Minister?

Winston Churchill led the Conservative Party as prime minister. He served as prime minister twice: from 1940 to 1945, during the Second World War, and again from 1951 to 1955.

Churchill’s political career was unusually complex. He began as a Conservative, crossed the floor to join the Liberal Party in 1904, and returned to the Conservatives in 1924. He later became Conservative leader in 1940, when he formed a wartime coalition government after Neville Chamberlain resigned.

His wartime leadership made him an international symbol of resistance to Nazi Germany, but the Conservatives lost the 1945 general election to Labour, led by Clement Attlee. Churchill then became Leader of the Opposition. He returned to Downing Street after the Conservatives won the 1951 election and remained prime minister until resigning in 1955.

The answer is sometimes complicated by Churchill’s earlier Liberal affiliation, but the question asks about the party he led while serving as prime minister. In both periods as prime minister, that party was the Conservative Party.