ABSTRACT
The by-elections of 1939–45 were so unlike normal by-elections that at first it is hard to make sense of them. There were no contests between the three main parties. At the outbreak of the war, under the Chamberlain government, the Chief Whips of the Liberal, Labour and Conservative parties concluded an electoral truce whereby, when a seat fell vacant, the party which had held it previously would nominate a candidate, while the other two parties agreed not to do so. The agreement was to last for the duration of the war, or until one of the signatories withdrew. The purpose of the arrangement was to preserve a measure of national unity by confining party differences to the House of Commons. When all three parties joined the Churchill Coalition in May 1940, the truce acquired a deeper significance, as an essential precondition of unity within the government. Hence, although the rank and file of the Labour Party at times grew very restless with an arrangement which protected a Conservative majority of over 200, the truce was never seriously in question. Of the 141 seats which fell vacant during the war, 66 were filled unopposed, by the nominee of the incumbent party. In the remaining 75 seats a contest was forced by Independents and minor party candidates. A new party, Common Wealth, was formed in 1942 as a direct result of the vacuum created by the truce, and won three by-elections against government candidates.
