Former Latin American leaders called Thursday for "free and fair" elections in Venezuela and the release of "political prisoners," in pointed criticism of the government ahead of a regional summit.
The 26 mostly conservative former heads of state, joined by two former Spanish prime ministers, issued the declaration on the eve of the Summit of the Americas in Panama, which Venezuela's leftist President Nicolas Maduro will attend.
The statement denounced a lack of press freedom in Venezuela and a crackdown on the opposition.
"The only possibility to re-establish democracy in Venezuela... is through rescuing the principle and system of separation of powers," the document says.
Such change is needed "to ensure free and fair elections" in Venezuela, which is to schedule legislative polls this year.
The signatories include former Colombian presidents Belisario Betancur and Andres Pastrana, Mexico's Felipe Calderon and Vicente Fox, and Argentina's Eduardo Duhalde.
Spain's former socialist premier Felipe Gonzalez and conservative counterpart Jose Maria Aznar also signed it.