Venezuelans will go to the polls on Sunday in the most consequential election in a quarter-century of socialist party rule, with President Nicolas Maduro confident of victory even as the Opposition has attracted impassioned support and warned of possible irregularities.

Opposition leader Maria Corina Machado has been the star of the coalition campaign, even after a ban on holding public office forced her to pass the torch to candidate Edmundo Gonzalez, a 74-year-old ex-diplomat known for his calm demeanour.

Gonzalez has won backing even from some former supporters of the ruling party, but the Opposition and observers have questioned whether the vote will be fair, saying decisions by electoral authorities and the arrests of Opposition staff are meant to create obstacles.

Maduro — whose 2018 re-election is considered fraudulent by the US, among others — has said the country has the world’s most transparent electoral system and has warned of a “bloodbath” if he were to lose.

People attending Maduro’s closing rally in Caracas on Thursday spoke enthusiastically of his late mentor — long-time socialist President Hugo Chavez — and said Maduro, in power since Chavez’s death in 2013, was continuing his predecessor’s legacy of helping the poor.

Venezuelan Opposition leader Maria Corina Machado

“Nicolas Maduro is building up the country and continuing the legacy of Commander Chavez,” said Conde Miranda, 54, who travelled from southern Ciudad Guayana to attend the rally.

Others alluded to a more challenging environment.

“Maduro has done both good things and bad things, the problem is the people below him,” said 30-year-old public employee Alejandro Goldteims.

Maduro’s government has presided over an economic collapse, the migration of about a third of the population, and a sharp deterioration in diplomatic relations, crowned by sanctions imposed by the US, European Union and others which have crippled an already struggling oil industry.

Maduro has said he will guarantee peace and economic growth, making Venezuela less dependent on oil income.

But many Venezuelans are tired of high inflation and public service cuts.

The minimum wage is equivalent to $3.50 per month, while basic food for a family of five is estimated to cost about $500.

Gonzalez and Machado, who have promised major changes and said a fresh start may motivate migrants to return, have urged people to hold “vigils” at polling stations. They have said they expect the military to uphold the results of the vote.