Who can initiate an optional referendum at the national level?

Federal Law on Popular Referendum (March 14, 2014)

Article 12. The following may request popular referendum:

I. The President of the Republic;

II. The equivalent to thirty-three percent of the members of any of the Chambers of the Congress, or

III. A Numbers of citizens equivalent to two percent of those registered on the voters’ registration list.

Citizens may support more that one popular referendum, but the processing of the referendum supported by the same citizens and that exceed twenty  percent of the support signatures will not proceed. In this case only the first application will apply. Failure to comply the prohibition above mentioned will be resolved according to the rules provided in Article 34, fraction IV of this Law.

In the case of Legislatuire - the equivalent to thirty-three percent of the members of any of the Chambers of the Congress; and in the case of registered electors - the equivalent to two percent of those registered on the voters’ registration list.