How many signatures are required to start the formal decision making stage of a direct democracy mechanism?

Political Constitution of Panama(Constitución Política de la República de Panam?).

https://www.constituteproject.org/constitution/Panama_2004.pdf

Article 314

A new Constitutionmay be adopted by a Parallel Constituent Assembly (Asamblea Constituyente

Paralela) whichmay be convened by decision of the Executive Branch, ratified by theLegislative

Branch withabsolute majority, or by the Legislative Branch with a favorable vote of twothirds of its members, or by popular initiative which must be signed by atleast twenty percent (20%) of citizens enrolled in the Electoral Register onthe thirty-first of December of the year preceding the initiative.

ElectoralCode 2007 (Código Electoral)

http://aceproject.org/ero-en/regions/americas/PA/panama-codigo-electoral-2012/view

Artículo 366. Para solicitar la revocatoria de mandato de unDiputado principal o suplente de libre postulaci?n, con fundamento en elnumeral 3 del art?culo anterior, se requerir? la firma del treinta por ciento(30%) de los ciudadanos que conformaban el Padr?n Electoral del circuitocorrespondiente al momento de su elecci?n. El procedimiento ser? reglamentadopor el Tribunal Electoral.

Artículo 371. Para solicitar larevocatoria de mandato de un Representante de Corregimiento por iniciativapopular, se requerir? de la firma del treinta por ciento (30%) de losciudadanos que conforman el Padr?n Electoral de la circunscripci?ncorrespondiente. El procedimiento ser?reglamentado por el Tribunal Electoral.