What to know about Brazil's run-off as Lula and Flávio Bolsonaro face off

Brazilians will be voting for a new president on Sunday in a run-off election in which the veteran incumbent, Luiz Inácio Lula da Silva, is being challenged by right-wing Senator Flávio Bolsonaro.

Bolsonaro, the son of convicted former president Jair Bolsonaro, beat Lula in the first round of voting on 4 October by a narrow margin, but fell short of the 50% of valid votes needed to win outright, triggering Sunday's run-off. Polls ahead of the second round put them neck and neck.

The election is being closely watched not just in Brazil, but also across Latin America and in the US, as a win for Bolsonaro would add Brazil to the list of Western Hemisphere countries aligned with the Trump administration.

Here's what you need to know.

While there were 12 candidates in the running in the first round, this election has always been about Lula and Bolsonaro.

The surnames on the ballots will be the same as those in the 2022 run-off, when Lula beat Flávio's father, Jair, by 1.8 percentage points.

What happened in the wake of that election has had a lasting and divisive impact on Brazil's political life.

Many of Jair Bolsonaro's supporters refused to recognise Lula's victory, and on 8 January 2023 - one week after the left-wing leader was sworn in - thousands stormed the Supreme Court, the presidential palace and the building housing Congress in the capital, Brasilia.

The security forces quickly managed to restore order and thousands were arrested.

Jair Bolsonaro was put on trial and found guilty of plotting a coup to overthrow Lula. He was sentenced to more than 20 years in jail.

Due to recurrent health problems, the older Bolsonaro is currently under house arrest rather than in a cell, but remains barred from running for office.

He has also had strict restrictions imposed on him, prohibiting him from posting on social media or making public statements.

Despite these restrictions, his shadow has loomed large over this election.

Lula and his Workers' Party have cast this election as a "battle for democracy", arguing that Jair Bolsonaro's conviction for coup-plotting is evidence that Bolsonarismo constitutes a threat to Brazil's democratic institutions.

Lula has also portrayed himself as the guarantor of Brazil's sovereignty, warning that a vote for his rival, who advocates closer ties to the Trump administration, would undermine Brazil's independence.

During Lula's latest term in office, relations with his US counterpart Donald Trump have been rocky.

Referring to what Trump has dubbed the "Donroe doctrine" - his administration's national security strategy which asserts that US dominance in the Western hemisphere should not be interfered with - Lula has insisted that "Brazil does not fit into anyone's backyard".

Flávio Bolsonaro, on the other hand, argues that working with the US to combat powerful criminal gangs - which wield immense power in parts of Brazil - will restore the state's sovereignty to gang-controlled areas.

He has also been labelling Lula's Workers' Party (PT) as corrupt, reminding voters of the massive financial scandals which plagued the PT for years and which have turned many voters against it.

The acrimonious attacks during the election campaign appear to have turned many people off voting altogether.

In the first round, a record 21% of those eligible to vote did not cast their ballots even though voting is mandatory for those aged between 18 and 70 and literate - with those who do not turn up facing a fine.

Some supporters of the left-wing Workers' Party (PT) said they were disillusioned that it had not found a new, younger candidate to stand for the presidency.

Lula has been president three times already.

When he started his third term in office in 2023, he vowed it would be his last, and yet his party endorsed him as their candidate again this year, even though he will turn 81 two days after the election.

Even backers of the PT will acknowledge that he achieved more in his first two terms - from January 2003 to December 2010 - than in this most recent four years in office.

He was widely praised for lifting millions out of poverty with the help of a cash-transfer programme called Bolsa Família and left office on 1 January 2011 with record approval ratings of over 80%.

But his political career suffered serious setbacks in the following years - he was convicted of corruption and sent to jail for more than 18 months.

Those convictions were annulled in 2021, leaving Lula free to run for the presidency in the 2022 election, in which he beat Jair Bolsonaro.

There is no doubt he remains a towering figure in the left. But while his supporters described him ahead of the 2022 election as the "saviour of the Amazon", praising his commitment to protecting the rainforest, some environmentalists have been critical of some of his recent actions.

His support for exploratory oil drilling in offshore waters near the mouth of the Amazon in particular has drawn criticism.

Lula insists that he remains committed to eventually phasing out fossil fuels and argues that oil revenues are key to financing Brazil's transition to clean energy.

His government has also pointed to the reduction in deforestation in the Amazon - satellite data suggests the area deforested in the first half of 2026 was reduced to its lowest in the past decade - as proof that its policies were working.

Flávio Bolsonaro, 45, is Jair Bolsonaro's eldest son and has been serving as a senator since 2019.

The younger Bolsonaro is running for the right-wing Liberal Party (PL) and, while he is widely seen as less confrontational than his father, he is appealing to the followers of the older Bolsonaro by promising to broadly continue in his footsteps.

During his time in the Senate, the trained lawyer has advocated a tough-on-crime stance, calling for longer sentences and laxer gun laws, arguing that "decent citizens" should be able to defend themselves from criminals.

He has successfully lobbied for the US to declare the Brazil-based criminal gangs Comando Vermelho (CV) and Primeiro Comando da Capital (PCC) as Foreign Terrorist Organizations, a move that was opposed by Lula.

The younger Bolsonaro has also courted evangelicals and the agricultural industry as part of his campaign.

He has said that he will cut what he says are unnecessary regulations and "get the state off farmers' backs".

Quizzed in an interview with Globo in August on whether he still believed - as he had said in 2019 - that climate change did not exist, he acknowledged that there had been "extreme climate events", but insisted that these events were "cyclical".

Flávio Bolsonaro has actively courted Trump and members of his administration by portraying himself as a loyal ally during a meeting at the White House in May.

More recently, he promised to join the US-led anti-crime alliance that the Trump administration has dubbed "Shield of the Americas", should he be elected.