Brazilian Senator Flavio Bolsonaro announced late Sunday that his legal team will formally petition to annul the country’s presidential runoff election following his narrow defeat to incumbent President Luiz Inacio Lula da Silva.

Addressing supporters shortly after the Superior Electoral Court (TSE) declared Lula victorious, the Liberal Party (PL) candidate launched a scathing attack against the Federal Supreme Court (STF) over its late decision to extend voting hours nationwide.

“We will engage our legal team and seek to have these elections annulled,” Bolsonaro said. “I will not accept that the rules of the game have been arbitrarily changed—once again—by Lula’s friends on the Federal Supreme Court.”

Bolsonaro focused his criticism on STF Justice Cristiano Zanin, who issued a last-minute ruling extending polling hours across Brazil until 7 pm Brasília time following emergency petitions regarding transport blockades and severe weather.

The defeated senator condemned the decision, pointing out that Justice Zanin previously served as Lula’s personal defense lawyer before his appointment to the high court.

Lula secured a historic fourth non-consecutive term with 51.76% of the valid votes (over 60 million ballots), edging out Bolsonaro, who received 48.24%.

The high-stakes election capped one of the most volatile campaign cycles in modern Brazilian history. Bolsonaro initially led the race on Oct. 4, taking 47% of the vote against Lula’s 45%. Lula’s runoff win makes him the first Brazilian presidential candidate to overcome a first-round deficit since the two-round electoral system was adopted in 1989.

The PL campaign's challenge is expected to trigger intense legal battles in Brasília as electoral authorities prepare to certify the final election results. (AA)