Conservative Brazilian Senator Flavio Bolsonaro has followed his imprisoned father’s lead by refusing to concede defeat to leftist President Luiz Inacio Lula da Silva, who won a historic fourth term in the presidential ‌election.

Bolsonaro, the son of former president Jair Bolsonaro, called into question a late-Sunday decision by a Lula-appointed Supreme Court justice that extended voting by two hours over alleged public transport irregularities.

He said he would ask for the result ‌to be annulled.

“It is impossible to recognise the election results, given the circumstances under which things unfolded,” Bolsonaro said.

US President Donald Trump suggested on Monday (local time), without providing evidence, that Brazil’s election was “rigged.”

“It looked like another rigged election, frankly,” he said.

Other world leaders quickly rallied behind Lula’s victory, with congratulations pouring in from the EU, Mexico, France, Canada, India and Russia.

Recently elected right-wing presidents in Colombia, Peru and Chile joined the ranks of leaders recognising Sunday’s results, but the Trump administration remained silent.

Investors stunned by Lula’s comeback, which defied private polling, hammered Brazil’s stock market, exchange rate and public debt, as markets reassessed the country’s fiscal outlook under Lula.

The scale of Bolsonaro’s loss – he trails Lula by more than four million votes – made it unlikely his efforts to annul the ‌vote would succeed, analysts ‌said.

Less than 35,000 votes, or some ⁠0.03 per cent of the total, were cast in the extra two hours of voting ordered by the Supreme Court, according to an analysis of electoral ​records by Insper professor Pedro Burgos.

Bolsonaro’s petition is also undermined by the fact that his campaign also sought a voting extension due to heavy rains in the conservative-leaning south.

Still, his refusal to concede could spark protests in a country where faith in the electoral system, and judicial independence, has been strained in recent years, observers say.

Jair Bolsonaro plunged Brazil into a deep democratic crisis after the election in 2022, when his supporters stormed government buildings in protest against the result. He later received a 27-year sentence for plotting a coup.

Lula’s victory defied polls, precedent and global anti-incumbent sentiment to put the brakes on a wave of right-wing election victories across Latin America. He trailed Bolsonaro in the first round, but managed to convince voters to come out for him in the runoff.

Rampant selling tore through financial markets at the shock result, as investors reversed positions that had largely been built around expectations of a Bolsonaro victory.

-AAP