his term (Article 60, Section 6 of the Federal Constitution), and in case of comprehensive change of the Federal Constitution (Article 44, Section 3 of the Federal Constitution). A binding referendum is optional in case of non-comprehensive changes in the Federal Constitution. Such facultative referendum is to be conducted if at least one third of the members of the National Council or the Federal Council requests it. There have only been two binding referendums in post-1945 Austria: The nuclear power referendum in 1978 and the European Union membership referendum which was called because accession to European Union was deemed to be a comprehensive change to the Constitution. Non-binding referendum The National Council has the power to call on a non-binding referendum on matters of great importance. Such a referendum is called by majority of members of the National Council. Results of such a referendum are advisory. There was one such referendum in post-1945 Austria: the conscription referendum in 2013 The "no" option won, and the National Council accepted the result of the referendum and acted accordingly. See also Electoral calendar Electoral system References External links Adam Carr's Election Archive Parties and Elections Austrian Federal Ministry of the Interior: Elections NSD: European Election Database - Austria publishes regional level election data; allows for comparisons of election results, 1990-2008