Requirements for a referendum to pass

Constitution 1993 (with amendments in 2000)

http://www.ecs.sc/resources/Constitution_.pdf

Article 91

1. The National Assembly shall not proceed on a Bill to alter Chapter I, Chapter III, this Article , Article 110 or Article 111 unless -a. the proposed alteration contained in the Bill has been approved on a referendum by not less than sixty percent of the votes cast in the referendum; […]

60% of the votes cast in the referendum is required.