Rio de Janeiro (Brazil) (AFP) - After a day of energetic rallies by their supporters, Brazil’s leftist President Luiz Inacio Lula da Silva and right-wing senator Flavio Bolsonaro will go head-to-head Sunday in their first debate, a week ahead of a bitter and divisive presidential runoff.

Bolsonaro, 45, son of the far-right former president Jair Bolsonaro, secured a shock first-round lead over Lula earlier this month, defying poll predictions.

The televised debate on Sunday evening is expected to be pivotal in an election race marked by scandals and insults that is likely to go down to the wire.

Ahead of the showdown, tens of thousands of supporters of Flavio Bolsonaro gathered along Sao Paulo’s Paulista Avenue.

Dressed in the yellow and green of the Brazilian flag, they chanted “Come back Bolsonaro!” The message underscored Jair Bolsonaro’s enduring support among Brazil’s conservatives, despite the former president serving a 27-year sentence under house arrest for plotting a coup after his failed 2022 election bid.

“The country is in a state of calamity. To make ends meet or buy anything, you have to work two or three jobs just to pay the bills,” said Sara Machado, 36, wearing a T-shirt with the slogan: “Right-wing. With pride.”

“I believe in change, in a better country, with Flavio Bolsonaro, because we’ve already experienced 20 years of a government defined by corruption … I want to try something new,” said 35-year-old bank employee Renan Pinhata.

The rally drew about 71,000 people, according to monitors at the University of Sao Paulo.

While Bolsonaro has led in polls since the first round, his edge slightly narrowed in two polls this week which showed him with 51 percent of voting intentions compared to 49 percent for Lula.

- Swimmers and singers for Lula -

In Rio de Janeiro, swimmers at Praia Vermelha arranged themselves in the water to spell out Lula’s name. Later, on Copacabana beach, iconic octogenarian singer Caetano Veloso was due to lead a “rally for democracy” in favor of the president.

The events come after a wave of demonstrations in major Brazilian cities that have re-energized a lackluster campaign by the country’s left since the first-round result.

Students and social movements have swarmed the streets protesting the possibility of another far-right government under the rallying cry “Never Again Bolsonaro.”

In Lula’s camp, there is an atmosphere of “restrained hope,” and awareness that a very tough battle lies ahead, a government source said Friday, requesting anonymity.

On the cusp of turning 81, Lula shook up his campaign for the second round, after admitting it had been the most “disorganized” of his decades-long political career.

He enlisted young leftist influencers to advise him on his social media strategy and began shooting video selfies in a bid to connect with voters.

- ‘Electoral opportunism’ -

Lula has unleashed a flurry of measures to win over voters.

On Wednesday, Congress approved a constitutional amendment guaranteeing two days of paid rest per week instead of one, a campaign pledge by Lula that will benefit millions of workers.

Flavio Bolsonaro, who had fiercely criticized the measure, made a last-minute switch and voted in favor of it.

“He voted out of electoral opportunism,” said Lula, who has said his rival is not fit to be “president of a neighborhood association.”

Lula has also pledged debt forgiveness for microentrepreneurs, university scholarships and the removal of fuel taxes.

Critics have slammed him for costly promises as Brazil is already battling soaring public debt.

“Lula deceives people to get votes,” Bolsonaro said in an interview on Friday.

Bolsonaro has doubled down on his tough-on-crime message at a time when security is voters’ main concern, and has also vowed to free his jailed father.

“Those who think I’m radical on public security haven’t seen anything yet,” he said this week, adding that El Salvador’s controversial model of mass incarceration of gang members “seems too mild.”