A student at a rally for President Lula da Silva Ione Wells São Paulo and Rio de Janeiro 7 minutes ago In the sprawling former industrial city of Osasco, shuttered factories have given way to a shopping malls and delivery app tech companies in what is now dubbed São Paulo's "Silicon Valley." The municipality voted for Brazil's left-wing President Luiz Inácio Lula da Silva in 2022 but switched to the right-wing Flávio Bolsonaro in the first round of Brazil's presidential election this month. Bolsonaro won that vote - and now the two men face a run-off on Sunday. Since 1989, every first-round winner has gone on to be elected president.

Like many of President Lula's traditional supporters, Gilberto Almazan, who leads a metalworkers' union here, is visibly worried.

He cries when he tells Lula's life story: a boy who grew up in hunger in the north-east, who became a metalworker, then a union leader, then a three-time president. But he's candid about how things have changed here and how the union movement that was so integral to Lula's support base is stuck in the "Middle Ages", and struggling to keep up.

"We had strong deindustrialisation here," Almazan says. "The profile of the working class changed. They are no longer predominantly industrial workers, they are service workers.

"Metal, chemical, textile factories disappeared. And five malls were built." The word "change" comes up repeatedly among Bolsonaro supporters here. Many struggle to name specific Bolsonaro policies they like but know they want to try something different: frustrated by the economy, crime and corruption in politics – even though Flávio has been faced accusations of corruption too, which he denies.

Tairine says high prices are a problem for her "He brings the hope of change, that we can have a different Brazil," says lawyer Gisele Bonfim in Osasco, who decided to vote for Bolsonaro after supporting Lula in 2022.

Lula's re-election campaign has been hampered by voters turning away from him. In some cases, their frustration drove abstention, which was higher than average this year, but others like Gisele actively wanted something new.

One major reason for that is Brazil's working class has transformed seismically in places like Osasco.

Near one large shopping mall lies an open-air market where this shift is noticeable. Everyone is touting products, armed with a portable card machine.

Tairine, who sells hot dogs, used to abstain from voting, even though - as voting is compulsory in Brazil - not going to the polls incurs a fine. This year, she plans to vote for Bolsonaro. She points to high taxes paid on "everything" she buys and says these make it "so difficult for a poor person" dealing with inflation, arguing "nothing has changed" since Lula became president again.

Flávio Bolsonaro has proposed cutting government spending, government ministries, and some taxes - though he has said he'd maintain some of Lula's flagship welfare programmes.

A new working class For his supporters, Lula is a working-class hero credited with advancing workers' rights through organising strikes and lifting millions of people out of poverty with generous social welfare programmes as president.

But across Brazil millions now work in the gig economy, a phenomenon Almazan calls "Uber-isation": driving for Uber, delivering food, or running small businesses from market stalls to providing at-home beauty treatments.

"There are a lot of workers who need more freedom, flexibility of days and hours," he says, rather than the welfare and collective action Lula offered.

Robson used to support Lula but has since switched to support Bolsonaro Richard Lapper, who has written biographies of both Lula and Jair Bolsonaro – Flavio's father who was president from 2019-2022 - says the rise of individualised work and the decline of manufacturing caused by globalisation are not unique to Brazil. But because Brazil industrialised late and deindustrialised early, he argues, the effects have been sharper here. He calls Lula a "victim of his own success."

Unemployment fell to a record low, and Brazil was taken off the United Nation's Hunger Map during Lula's current presidency. But Lapper describes a crisis of "expectations" where people are now better off but don't feel it because prices have risen and household debt and interest rates are high.

Robson, 53, is a municipal civil servant in Osasco. Originally from Lula's north-eastern home state of Pernambuco, he grew up supporting him.

But he describes a country now running deficits and says its citizens are enduring the "worst phase" of its tax burden, which he blames on the Lula government's "mismanagement" of the economy and high public spending. "Now you have to make choices: pay an instalment for your car, or put food on the table," he says.

Lula's comeback strategy In some areas, Lula lost votes compared to 2022, even though Bolsonaro did not gain more than his father did then: 33 million people did not vote in the first round, the highest abstention since 1998.

In response, Lula's campaign has focused on mobilising hundreds of thousands of people – particularly students – on to the streets to get the vote out for round two. It claims one rally in São Paulo attracted about a million people.

"A lot of people didn't vote, they thought it wouldn't change anything," says one supporter, Leila. "Our fight is to make those people believe their vote changes things." Aerial videos of these huge demonstrations have been plastered across social media. An image of a topless man with a six-pack waving a Lula flag at one has been shared tens of millions of times.

The strategy is that their revolution will not be televised, but it should ideally go viral.

Lula, 80, has also been using social media to dismiss criticisms that he is past his prime: calling himself the "king of selfies" and posting videos showing him running from A to B on the campaign trail.

Some people who live in the favelas fear security forces entering if Bolsonaro is elected In Maré, one of Rio's largest favelas which is controlled by rival gangs, abstention was higher than average.

This dented Lula's support, even though he still won here: among Brazil's very poorest, Lula's welfare initiatives clearly do still resonate. One 18-year-old mother in Maré, Vitoria, earns less than £300 a month and praises Lula's government for increasing the minimum wage, giving workers the right to two days off, and providing essential medicines for free.

She is sceptical of Bolsonaro's plans to designate the gang which controls this part of the favela, Comando Vermelho, as a terrorist organisation, which he lobbied the US to do earlier this year.

She thinks it will lead to authorities entering the favela to "kill, destroy, ruin families, leave blood and bodies on the ground", citing a police raid in Rio last year that killed more than 130 people.

Another resident, Andreza Dionísio, blames high abstention rates here on both last-minute changes to polling station locations, but also "a sense of hopelessness about the future." Many Brazilians now worship in evangelical churches like the Assembleia de Deus Vitória em Cristo Increasingly, that void of hope is being filled by the growth of the evangelical church: about a quarter of Brazilians are now evangelical. Its mega-churches offer not just a spiritual home but support with issues like childcare, employment advice and even food. Its conservative pastors are some of Brazil's most powerful political operators.

Silas Malafaia, who has millions of followers on social media, leads the Assembleia de Deus Vitória em Cristo headquartered in the lower middle-class neighbourhood of Penha in Rio de Janeiro. He is being investigated for allegedly obstructing the coup trial of Jair Bolsonaro, which he denies and calls politically motivated.

At one two-hour sermon he preaches messages of self-improvement to an emotional crowd of hundreds, interrupted occasionally for live music interludes and breaks to collect money with card machines. The whole event is live-streamed on YouTube.

Afterwards, in his office adorned with a photo of him and the former president Jair Bolsonaro, at whose wedding he officiated, he told the BBC that without the evangelical church in working-class neighbourhoods the country would be "in a state worse than you can imagine".

"It gives these people meaning. To better their lives." Pastor Silas Malafaia officiated at Jair Bolsonaro's wedding He argues Flávio Bolsonaro shares the church's values: for family, and against gender "ideology" and abortion.

The church is driving some to actively vote for Flávio Bolsonaro, but among much of Brazil's new working class, the first round feels more like a rejection of President Lula than an endorsement of his rival.

"There will never be another Lula," Gilberto Almazan fears. He intends this as a compliment, but Brazil's changing world of work means it's also probably true.

While Lula's past story still stirs great emotion for people like Almazan, his political fate may depend on whether voters think he can now offer Brazil a new one.