CARACAS (Dispatches) – Some Venezuelans went to the polls Sunday in a vote organized by the pro-Western opposition aimed at gauging public support for Maduro's plan to rewrite the constitution, against a backdrop of worsening political violence.
Authorities are refusing to greenlight a vote presented as an act of civil disobedience and supporters of President Nicolas Maduro have boycotted it.
 The "plebiscite" comes two weeks ahead of a Maduro-backed vote to elect a citizens' body that would revise the constitution. The opposition has told its supporters to stay away.
The opposition’s muscle flexing is stoking fears of more riots and running street battles with police, which have been persistent for the past three and a half months. Nearly 100 people have died in the unrest since the beginning of April.
While Maduro is deeply unpopular among the protesters, he enjoys backing from mostly poor parts of the population and, most importantly, from the military.
Maduro, giving a national radio and TV broadcast, portrayed the vote as merely an "internal consultation by the opposition parties" with no electoral legitimacy.
"I call on all Venezuelans to participate peacefully in political events tomorrow, with respect for others' ideas, with no incidents. Peace is what I ask," he said.
He said the opposition was tied to foreign powers - implied to be the "imperialist" United States - with the aim of toppling his government. The international media, he said, was covering the opposition vote in a way to justify foreign intervention.
Five former Latin American presidents - from Bolivia, Colombia, Mexico and two from Costa Rica - were in Venezuela at the opposition's invitation to act as observers of the vote, alongside electoral experts from various countries.
Former Mexican leader Vicente Fox said on arriving in Caracas that the vote could be the "beginning of the end" of Maduro's government.
On Friday, UN Secretary-General Guterres said talks were "urgently" needed between the opposition and government to stem the violence and find a "constitutional path" to peace.
Latin America expert Isaac Bigio said the opposition is calling for a referendum to topple Maduro and if the method does not work, they will push for a military coup.
The referendum is not going to have "any legal binding” but "the opposition will try to use that to little by little undermine this government” and to ask for a military "coup d'état” against President Maduro, he told Press TV on Sunday.