The Statute of Westminster Adoption Act 1942 (Cth) formally adopted the Statute of Westminster 1931 in Australia, backdating its effect to 3 September 1939—the date of the commencement of the Second World War. This backdating was important to validate wartime legislation that may have been inconsistent with United Kingdom law. The adoption confirmed that the Commonwealth Parliament could legislate inconsistently with Imperial legislation, a significant step in Australia's progression toward full legislative independence.