Issues in relation to which referendums are mandatory at the national level
Serbia
Answer
Constitutional amendments
Source
Article 203: Proposal to amend the Constitution and adoption of the amendment to the Constitution
[...]
The National Assembly shall be obliged to put forward the act on amending the Constitution in the republic referendum to have it endorsed, in cases when the amendment of the Constitution pertains to the preamble of the Constitution, principles of the Constitution, human and minority rights and freedoms, the system of authority, proclamation the state of war and emergency, derogation from human and minority rights in the state of emergency or war or the proceedings of amending the Constitution.
Comment
Referendum is only mandatory when amendment is related to specific issues (see Source).
