An independence referendum was held in Montenegro on 21 May 2006. It was approved by 55.5% of voters, narrowly passing the 55% threshold. By 23 May, preliminary referendum results were recognized by all five permanent members of the United Nations Security Council, indicating widespread international recognition of Montenegro once independence would be formally declared. On 31 May the referendum commission officially confirmed the results of the referendum, verifying that 55.5% of the population of Montenegrin voters had voted in favor of independence. Because voters met the controversial threshold requirement of 55 pproval set by the European Union, the referendum was incorporated into a declaration of independence during a special parliamentary session on 31 May. The Assembly of the Republic of Montenegro made a formal Declaration of Independence on Saturday 3 June.