Following threats of violence from followers of his far-right predecessor Jair Bolsonaro, leftist leader Luiz Inacio Lula da Silva will take the oath of office as president of Brazil on Sunday amid increased security in the nation’s capital.

After the ceremony in Congress, Lula will walk to the Planalto palace to don the presidential sash in front of a gathering of 30,000 supporters. Around 300,000 people are anticipated to assemble to celebrate on the esplanade in Brasilia.

Lula, 77, narrowly defeated Bolsonaro in October to win an unprecedented third presidential term after a hiatus that saw him spend a year and a half behind bars on corruption convictions that were later overturned.

In his previous years as Workers Party (PT) president from 2003-2010, the former union leader lifted millions of Brazilians from poverty during a commodity boom that buoyed the economy.

Now, he faces the daunting challenge of improving Brazil’s stagnant economy while also uniting a country that has become painfully polarized under Bolsonaro.

“A lot is expected of Lula. He’ll have the difficult mission to restore normality and predictability in Brazil, and above all to rapidly deliver results that improve the quality of life for its inhabitants,” said Creomar de Souza, director of Dharma Political Risk consultancy in Brasilia.

Bolsonaro left Brazil for Florida on Friday, avoiding having to hand over the sash to his rival, whose victory he has yet to recognize, while also removing himself from any immediate legal risks related to his time in office.

His supporters have protested for two months that the election was stolen and called for a military coup to stop Lula returning to office in a climate of vandalism and violence.

One supporter was arrested for making a bomb that was discovered on a truck laden with aviation fuel at the entrance to Brasilia airport, and confessed he was seeking to sow chaos to provoke a military intervention.

In a thinly veiled dig, acting President Hamilton Mourao, who was Bolsonaro’s vice president, criticized his former boss for failing to lead the country and allowing anti-democratic sentiment to thrive after his October defeat at the polls.

“Leaders who were supposed to reassure and unite the nation … allowed silence or inopportune and deleterious protagonism to create an atmosphere of chaos and social disintegration,” Mourao said in a speech on Saturday night.

Mourao defended Bolsonaro’s four years in power for leaving a strong economy, but criticized environmental backsliding after deforestation in the Amazon reached a 15-year-high.

Tens of thousands of Lula fans descended on central Brasilia for the celebrations on Sunday, and authorities sent 10,000 police and soldiers to increase security and search attendees—who are not allowed to bring bottles, cans, flag masts, or toy guns—as they arrived. Also temporarily prohibited was citizens carrying weapons.

The king of Spain is among the 19 heads of state and government and 50 delegations from 50 different countries that have confirmed their attendance, according to the organizers.

Before leaving for Florida on Friday, Bolsonaro gave a somber speech to the nation in which he called the bomb plan a “terrorist act” and congratulated his followers for rallying in front of army installations across the nation to demand a coup.