Venezuela is voting on Sunday to elect a legislative body tasked with reforming the Constitution, in a poll which has triggered international alarm and deadly street protests against President Nicolas Maduro.
Maduro predicted a "big victory" in the election of the 545-member citizens' Constituent Assembly empowered to dissolve the opposition-controlled parliament and rewrite the Constitution.
The opposition has urged a boycott, saying the vote marks a move towards "dictatorship" by an unpopular president desperate to cling to power with the backing of a loyal military.
Al Jazeera's John Holman, reporting from Caracas, said that the opposition feels that the vote is stacked against them in favour of government supporters.
"A leading newspaper here summed up this vote when it said, 'The government is choosing its representatives,' as no opposition candidates are taking part in it."
Four months of street protests against Maduro have left more than 100 people dead, and exposed deep political divisions in this oil-rich nation reduced to economic calamity.
Demonstrations tapered off just before Sunday's vote after Maduro decreed a ban threatening prison terms of up to 10 years for protesters.
But fear of violence worsening has rippled across the region, and beyond.
Several foreign airlines, including Air France, Delta, Avianca and Iberia have suspended flights to the country.
|Maduro decreed a ban on protesters threatening prison terms of up to 10 years for those who attend rallies [AFP]|
Families of US diplomats have been ordered to leave following the imposition of American sanctions on 13 current and former Venezuelan officials.
Maduro - who described the Constituent Assembly as a "card that will win this game" - on Saturday said the vote was "the most important election held in Venezuela's political system".
Authorities on the eve of the vote said all was ready for the nationwide balloting, although the head of the electoral council acknowledged some voting machines had been burned in attacks on polling stations.
|Anti-government activists clash with riot police during a protest in Caracas in a show of defiance to President Nicolas Maduro [AFP]|
Freddy Guevara, an opposition politician, said further demonstrations would take place on Sunday.
"There will not be calm as long as the people don't have peace," he said.
Colombia and Panama - refuges for tens of thousands of Venezuelans fleeing the chaos at home - have said they will not recognise the results of Sunday's election in Venezuela.
At an overnight protest in Villa del Rosario, a Colombian town on the Venezuelan border, hundreds of Venezuelans taking shelter there decried the election.
|Crisis gripping Venezuela turned deadlier in advance of a controversial election that has earned international scorn [AFP]|
"We don't know what's going to happen in this situation created by this president," said one of them, Bella Buitrago, 48. "We're all extremely nervous".
"We don't want Mr Maduro ... he should leave the country," said another, Sindry Borges.
Some in Maduro's administration have broken ranks with him, most prominently his attorney general. Two diplomats resigned this week in dissent: one at the UN and another at the embassy in Panama.
The Venezuelan leader has blamed the mounting unrest against him and his policies on the US, working hand-in-hand with the Venezuelan opposition to wage an "economic war".
Source: Al Jazeera and news agencies