By Gabriel Araujo

SAO PAULO, Sept 7 (Reuters) - Brazil's opposition took to the streets on Independence Day on Monday as right-wing presidential candidate Senator Flavio Bolsonaro sought to capitalize on a Supreme Court crisis to bolster his campaign against leftist President Luiz Inacio Lula da Silva in next month's election.

In chilly temperatures, some 28,500 people massed on Sao Paulo's Paulista Avenue for the conservatives' rally, researchers from the University of Sao Paulo's Monitor do Debate Politico estimated.

Organizers cast the demonstration as a protest against Lula's government and Supreme Court Justice Alexandre de Moraes ahead of first-round voting on October 4.

The justice aggressively pursued former President Jair Bolsonaro, the senator's father, over a 2023 coup plot and won his conviction in 2025, making Moraes one of Brazil's most polarizing figures.