Sections 73A and 73B rely on the Commonwealth's legislative powers under paragraph 51(xxix) (external affairs) of the Constitution as it relates to giving effect to Australia's obligations under relevant international agreements, in particular:
(a) paragraph 1 of Article 3 and paragraph 1 of Article 4 of the Ramsar Convention; and
(b) subparagraphs (a), (c) to (e) and (k) of Article 8 and subparagraph (a) of Article 10 of the Biodiversity Convention.