Mandatory Referendum

In the last main type, the competencies for launching a vote are assigned to law, usually the constitution, whereas the competencies for the voting issue rests with the representative institutions. Some constitutions prescribe that a public vote must be held when the legal status quo of a particular matter is changed by the law-making institutions. 

This can either be the constitution itself, electoral laws, or international treaties. In these cases, a vote is mandatory. Almost all typologies include a mandatory referendum as a proper type (for example Moeckli, 2021; Vatter, 2009: 128; Morel, 2007; Hornig, 2011).