Luiz Inácio Lula da Silva has acknowledged that the first-round election result was not what he had expected, after no opinion poll predicted that the leftist president seeking re-election would finish behind his rival, Flávio Bolsonaro, according to El País.

With 99.9% of ballots counted, Lula stands at 45% of the vote against 47% for his opponent in the first round held on Sunday.

"The result, many times, is unexpected. One never achieves everything one wanted," Lula said on election night.

Lula, 80, said he would fight hard to reverse the outcome in the second round that both candidates will contest on 25 October. Speaking from a hotel in central São Paulo that served as the Workers' Party's election bunker, he said the runoff "is the moment to show the true photograph of Brazil today and of the Brazil we want".

He also attacked his rival's record, describing Flávio Bolsonaro as having "a dark biography, with dark links", and urged voters who abstained in the first round to turn out for the runoff.