Statute of Westminster, (1931), statute of the Parliament of the United Kingdom that effected the equality of Britain and the then dominions of Canada, Australia, New Zealand, South Africa, Ireland, and Newfoundland.
The statute implemented decisions made at British imperial conferences in 1926 and 1930; the conference of 1926 in particular declared that the self-governing dominions were to be regarded as “autonomous communities within the British Empire, equal in status, in no way subordinate one to another in any aspect of their domestic or external affairs, though united by a common allegiance to the Crown, and freely associated as members of the British Commonwealth of Nations.” The statute itself recognized the sovereign right of each dominion to control its own domestic and foreign affairs, to establish its own diplomatic corps, and (except for Newfoundland) to be separately represented in the League of Nations. It was also stated that “no law hereafter made by the Parliament of the United Kingdom” or by any dominion parliament “shall extend to any of the said Dominions as part of the law of that Dominion otherwise than at the request and at the consent of that Dominion.”
The statute left many difficult legal and constitutional questions unsettled—e.g., the functions of the Crown, the possibility of one or more of the autonomous communities remaining neutral while others are at war, and so forth—but mutual forbearance and constant consultation between the different units made the formula remarkably successful in operation.