CARACAS/BARINAS (Reuters) - Several hundred Venezuelan opposition demonstrators blocked traffic in a march to the Organization of American States (OAS) headquarters in Caracas on Wednesday to protest this weekend’s presidential vote, which they say is rigged.

Security personnel uses a monocular while Venezuela's President Nicolas Maduro delivers his speech to supporters during a campaign rally in Charallave, Venezuela May 15, 2018. REUTERS/Carlos Garcia Rawlins

With the mainstream opposition boycotting Sunday’s election and two of their most popular leaders barred from standing, leftist President Nicolas Maduro is expected to win re-election despite Venezuela’s crushing economic crisis.

Wednesday’s march, a far cry from months of mass protests that drew hundreds of thousands onto the streets last year, was led by a recently-formed new opposition grouping called Broad Front, which is promoting abstention.

“I’m not going to vote because it’s all fixed in advance,” said Nancy Forrero, 54, an engineer for a private oil company.

“This is a dictatorship,” added Forrero, whose son has moved to Buenos Aires. Tens of thousands of Venezuelans have left their country for other places in South America in a growing exodus of migrants escaping high inflation and food shortages.

Chanting anti-Maduro slogans and waving the flags of militant opposition parties Justice First and Popular Will, the protesters planned to deliver a letter to the OAS office.

“We want free, transparent, true elections, not what’s going to happen on Sunday, a farce,” said economist Ivan Lopez, 65.

The abstention push has split Venezuela’s opposition and played into Maduro’s hands.

His main rival is a former state governor, Henri Falcon, who broke with the opposition coalition to run, arguing the only way to defeat Maduro was at the ballot box.

“Those promoting abstention are not offering any alternative, they want a foreign military intervention, but it is we Venezuelans who have to resolve our problems,” Falcon told Reuters at a rally in Barinas state on Tuesday night.

While polls are mixed and unreliable due to the anticipated larger-than-usual abstention, some do show Falcon ahead of Maduro. However, Maduro benefits from the ruling Socialist Party’s election machinery, the vote-winning power of state food handouts, and an election board controlled by loyalists.

The United States, European Union and various Latin American nations have already condemned Sunday’s vote conditions as unfair, and U.S. President Donald Trump is considering adding oil sanctions to measures already taken to stop Venezuela issuing more debt.

In an interview with French TV channel France 24 released on Wednesday, Maduro condemned those international actions as “unacceptable threats” to sovereignty and insisted Venezuela’s democracy was “impeccable.” He also said there may be a referendum after the election to revoke opposition legislators in the National Assembly.

“It seems a very good idea,” he said, of the idea being floated by the entirely pro-Maduro Constituent Assembly, which has taken over the opposition-run legislature’s functions.