Who can initiate an optional referendum at the national level?

Albania, Constitution 1998, (last amended in 2020), accessed 31 August 2022

Article 150

1. The people, through 50 thousand citizens, who enjoy the right to vote, have the right to a referendum for the abrogation of a law, as well as to request the President of the Republic to hold a referendum about issues of special importance.

2. The Assembly, upon the proposal of not less than one-fifth of the deputies or the Council of Ministers, can decide that an issue or a draft law of special importance be presented for referendum.

3. Principles and procedures for holding a referendum, as well as its validity, are provided by law.

Article 177

1. Initiative for revision of the Constitution may be undertaken by not less than one-fifth of the members of the Assembly.

2. No revision of the Constitution may be undertaken during the time when the extraordinary measures are taken.

3. The draft law is approved by not less than two-thirds of all members of the Assembly.

4. The Assembly may decide, with two-thirds of all its members that the draft constitutional amendments be voted in a referendum. The draft law for the revision of the Constitution enters into force after ratification by referendum, which takes place not later than 60 days after its approval in the Assembly.

5. The approved constitutional amendment is put to a referendum when this is required by one-fifth of the members of the Assembly. […]