Luiz Inácio Lula da Silva won Brazil's runoff after trailing in the first round, adding 10m votes, with Amazon deforestation policy at stake in his term.
A WhatsApp channel run by Congressman André Janones grew to 10.8 million followers and, allies say, helped Lula overturn his deficit to Flávio Bolsonaro in about three weeks.
Lula's election victory in Brazil complicates Donald Trump's push for a right-aligned Latin America, after Trump called the vote 'rigged' while praising Lula.
Luiz Inácio Lula da Silva takes 51.79% of the second round to win a fourth term, while Flávio Bolsonaro refuses to recognise the result and calls for annulment.
Brazil's run-off pits Lula against Flávio Bolsonaro after former industrial cities like Osasco swung right, with 33 million abstentions in the first round.
US Senator Bernie Sanders and 11 Democratic lawmakers ask Meta's Mark Zuckerberg to explain alleged unequal treatment of the Lula and Bolsonaro campaigns.
Brazil's Amazon deforestation fell 41.8% in the year to July 2026, the biggest drop since records began in 1988, ahead of the 25 October presidential run-off.