Voters in crisis-hit Venezuela are heading to the polls in presidential elections expected to hand President Nicolas Maduro a second six-year term.

About 20.5 million people are eligible to vote on Sunday but many analysts expect a low turnout after the opposition alliance Democratic Unity Roundtable (MUD) called on voters to boycott the poll.

Maduro, the political heir of late socialist president Hugo Chavez, only faces three lightweight candidates.

They are former Lara state governor Henri Falcon, evangelical pastor Javier Bertucci and Chavist dissident Reinaldo Quijada.

MUD sees the elections as a “farce” only aimed at legitimising the continuation of Maduro’s rule.

The president’s electoral campaign had the support of the state apparatus and suspicion is rife the pro-government electoral authority could rig the results.

The United States, 14 Latin American countries and the European Union have denounced the elections as undemocratic.

The US on Friday added top ruling party official Diosdado Cabello and three other Venezuelans to its list of individuals targeted in Maduro-related sanctions.

– AAP