Issues in relation to which referendums are optional at the national level

Lesotho
Answer
Any issue of national importance
Source
Constitution 1993 (last amended in 2011)
Article 84B.
1. The King may, on the advice of the Prime Minister order that a referendum be conducted to obtain the opinion of the electors on any matter he considers to be of national interest.
2. Parliament may make provision fo rthe conduct of a referendum.