Nicaraguans go to the polls Sunday for presidential elections dismissed as a "sham" by the international community, with all viable challengers to long-term leader Daniel Ortega locked up or in exile.

As Ortega, 75, prepared to claim a fourth consecutive term -- his fifth overall -- the United States described Nicaragua as a "cautionary tale" with a regime "determined to hold on to power at any cost."

"It will be quite clear that these elections will have no credibility, that they're a sham," Patrick Ventrell, the US State Department's Central American Affairs director said Thursday.

"We are going into a scenario where you have a dictatorship, and we'll have to respond to such."

Daniel Ortega and his wife and vice-president Rosario Murillo are accused of running an authoritarian regime
Daniel Ortega and his wife and vice-president Rosario Murillo are accused of running an authoritarian regime AFP / Oswaldo Rivas

Just over three years after massive protests against his rule and a violent crackdown that claimed more than 300 lives, Ortega is assured another five-year term with his wife and vice-president, Rosario Murillo, 70, by his side.

Seven people who had any real shot at the presidency are among 39 opposition figures detained in a brutal government clampdown that started in June.

Ortega, the leader of the Sandinista National Liberation Front (FSLN), faces five opponents, though in name only -- all are derided as regime collaborators.

The vote in Central America's poorest country will take place without international observers and with most foreign media denied access to the country.

Nicaragua's last opposition daily, La Prensa, had its director thrown in prison in August, and Facebook announced this week it had closed a government-operated troll farm spreading anti-opposition messages.

Profiles of seven potential presidential candidates under arrest in Nicaragua ahead of elections on Nov 7
Profiles of seven potential presidential candidates under arrest in Nicaragua ahead of elections on Nov 7 AFP / Nicolas RAMALLO

Amid the suppression, fear vies with apathy among Nicaragua's 4.3 million eligible voters. Voting is not mandatory in the country of 6.5 million.

"There is no one to vote for. Daniel (Ortega) has it in the bag," a 46-year-old woman told AFP at her home in Masaya, 35 kilometers (20 miles) south of the capital Managua.

She asked not to be named. "One cannot talk. You'll go to jail," she said.

More than 30,000 Nicaraguan police and military have been deployed to guard more than 3,000 polling stations
More than 30,000 Nicaraguan police and military have been deployed to guard more than 3,000 polling stations AFP / STRINGER

A firebrand Marxist in his youth, Ortega ruled Nicaragua from 1979 to 1990, after the guerrilla ousting of US-backed dictator Anastasio Somoza Debayle.

Returning to power in 2007, he has won reelection three times, becoming increasingly authoritarian and quashing presidential term limits.

Two-thirds of respondents in a recent Cid-Gallup poll said they would have voted for an opposition candidate on Sunday.

The favorite was Cristiana Chamorro, daughter of Violeta Barrios de Chamorro who is the only person to have beaten Ortega in an election, in 1990.

Profiles of seven potential presidential candidates under arrest in Nicaragua ahead of elections on Nov 7
Profiles of seven potential presidential candidates under arrest in Nicaragua ahead of elections on Nov 7 AFP / Nicolas RAMALLO

But Chamorro is under house arrest, and six other presidential hopefuls are behind bars in conditions their family members say amount to torture.

The jailed opposition figures are accused of unspecified attacks on Nicaragua's "sovereignty" under a law passed by a parliament dominated by Ortega allies, who also control the judicial and electoral branches.

Election authorities have banned the country's main opposition alliance, Citizens for Freedom, from contesting Sunday's vote, just like in 2016 when Ortega won unopposed.

Three political parties and dozens of civic organizations are prohibited.

A grouping of Nicaraguan and international NGOs this week urged the United Nations to investigate "gross human rights violations" under Ortega's rule.

"Ortega will continue in power... and the repression against those who defend human rights and think differently to the regime will likely worsen," said the group that calls itself Colectivo 46/2.

Apart from about 150 political opponents known to be behind bars, more than 100,000 Nicaraguans are in exile to avoid arrest -- mainly in Costa Rica, Miami and Madrid.

For Ortega -- whose main allies are Venezuela, Cuba and Russia -- his jailed critics are not political prisoners but "criminals" seeking to overthrow him with US backing.

The wave of arrests has worsened ties with the United States and European Union, who have imposed sanctions against Ortega family members and allies.

The EU's foreign policy chief, Josep Borrell, has branded Ortega a "dictator" staging "fake" elections, and on Wednesday, the US Congress approved a law to ramp up punitive measures.

In the United States, Europe and other Latin American countries, opponents of the Ortega regime are planning protests for Sunday and agitating for a boycott of the vote.

In Nicaragua itself, gatherings of more than 200 people are banned, ostensibly as a coronavirus prevention measure.

More than 30,000 police and military have been deployed to guard 3,000 polling stations.

Polls are due to open at 13H00 GMT (7:00 am) and close 11 hours later.

The results, predictable as they are, are expected the same day.