A staffer connects the electronic ballot box at a polling station on the eve of the presidential election in Brasilia on October 1, 2022.
A staffer connects the electronic ballot box at a polling station on the eve of the presidential election in Brasilia on October 1, 2022.

Brazil votes Sunday in a polarizing presidential election, with all eyes on whether front-runner Luiz Inacio Lula da Silva can win in a single round -- and whether incumbent Jair Bolsonaro will accept the result.

The campaign, which left the Latin American giant deeply divided, ended with former president Lula (2003-2010) leading ex-army captain Bolsonaro with 50 percent of valid votes to 36 percent, according to a final poll from the Datafolha institute released Saturday evening.

The figures put Lula on the cusp of the score needed to win outright and avoid a runoff on October 30: half the valid votes, plus one.

But Bolsonaro, known for his combative style, has repeatedly said "only God" can remove him from office, attacked supposed fraud in Brazil's electronic voting system, and vowed his re-election bid can have just three outcomes: "prison, death or victory."

Lula, the charismatic but tarnished ex-president seeking to stage a comeback at 76, says he fears the incumbent will create "turmoil" if he loses -- a concern heard often in Brazil heading into election day.

Bolsonaro's attacks on the voting system have raised fears of a Brazilian version of the riots that erupted at the US Capitol last year after his political role model, former president Donald Trump, refused to accept his election loss.

"I do think (Bolsonaro) will contest the election result if he loses," said political analyst Adriano Laureno of consulting firm Prospectiva.

"But that doesn't mean he'll succeed. The international community will recognize the result quickly... There might be some kind of turmoil and uncertainty around the transition, but there's no risk of a democratic rupture."

Observers from the Organization of American States, the Carter Center, the Inter-American Union of Electoral Organizations (UNIORE) and other international bodies will be monitoring the vote.

The White House meanwhile said the United States would be watching the vote "closely."

More than 500,000 security-force members will be deployed on election day.

Public Security Minister Anderson Torres sought to downplay fears of unrest.

"We're having an election, not a war," he said.

Lula, the ex-metalworker who rose from destitute poverty to become the most popular president in Brazilian history, is seeking to stage a remarkable return, four years after falling spectacularly from grace when he was jailed for 18 months on controversial corruption charges.

Accused in a massive graft scheme centered on state-run oil company Petrobras, Lula regained the right to run for office last year when the Supreme Court annulled his convictions, ruling the lead judge in the case was biased.

In the meantime, Bolsonaro, 67, who swept to office on a wave of anti-establishment outrage in 2018, has lost his outsider shine.

Vowing to defend "God, country and family," the president retains the die-hard backing of his "Bibles, bullets and beef" base -- Evangelical Christians, security hardliners and the powerful agribusiness sector.

But he has lost moderate voters with his management of the weak economy, his vitriolic attacks on Congress, the courts and the press, a surge in destruction in the Amazon rainforest, and his failure to contain the devastation of Covid-19, which has claimed more than 685,000 lives in Brazil.

Many voters are deeply disillusioned with both contenders -- and the lack of other options -- in a race where none of the other nine candidates managed to break out of single digits in the polls.

"It's like we have a gun to our heads," 27-year-old Uber driver Matheus Fernandes told AFP in Lula's home state of Pernambuco.

His plan: cast a blank ballot.

Lula plans to vote in Sao Bernardo do Campo, outside Sao Paulo, where he rose to prominence as a union leader. Bolsonaro, a former Rio de Janeiro congressman, will vote in the iconic beach city, then return to Brasilia to watch the results.

The polls open at 8:00 am and close at 5:00 pm (1100-2000 GMT), with results expected some two hours later.

Brazil's 156 million voters will also be electing the lower house of Congress, one-third of the Senate and governors and state legislators in all 27 states.

Brazilian president Jair Bolsonaro waves at supporters during a motorcade in Joinville, Brazil on October 1, 2022, on the eve of the presidential election
Brazilian president Jair Bolsonaro waves at supporters during a motorcade in Joinville, Brazil on October 1, 2022, on the eve of the presidential election
Brazil presidential candidate Luiz Inacio Lula da Silva greets supporters during a campaign rally on the eve of the presidential election in Sao Paulo,on October 1, 2022
Brazil presidential candidate Luiz Inacio Lula da Silva greets supporters during a campaign rally on the eve of the presidential election in Sao Paulo,on October 1, 2022
The Christ the Redeemer statue is illuminated with the message "Peace in the Elections" in Rio de Janeiro on October 1, 2022
The Christ the Redeemer statue is illuminated with the message "Peace in the Elections" in Rio de Janeiro on October 1, 2022