World War II's broader scope required passage of the National Resources Mobilization Act to supplement the powers in the War Measures Act to pursue the national war effort. The extent to which wartime federal power could expand was further clarified in the "Chemicals Reference" (which held that Orders in Council under the War Measures Act were equivalent to acts of parliament) and the "Wartime Leasehold Regulations Reference", which held that wartime regulations could displace provincial jurisdiction for the duration of an emergency. Additional measures were required in order to secure control of the economy during that time. Jurisdiction over unemployment insurance was transferred permanently to the federal sphere; the provinces surrendered their power to levy succession duties and personal and corporate income taxes for the duration of the war (and for one year afterwards) under the Wartime Tax Rental Agreement; and labour relations were centralized under federal control with the Wartime Labour Relations Regulations (lasting until 1948), in which the provinces ceded their jurisdiction over all labour issues.