FILE - In this April 7, 2018 file photo, Brazil's former President Luiz Inacio Lula da Silva waves to supporters from a window of the Metal Workers Union headquarters in Sao Bernardo do Campo, Brazil, before he was later jailed for corruption on the same day. Imprisonment has not knocked the former president out of the lead in Brazil’s upcoming presidential race. He also leads in all proposed runoff combinations. (AP Photo/Nelson Antoine, File)

SAO PAULO - Even imprisonment hasn't knocked former President Luiz Inacio Lula da Silva out of the lead in Brazil's presidential race.

A poll released Sunday by the Datafolha institute shows the centre-leftist with a 2-1 advantage over his nearest rival under one election scenario.

It's the first survey of Brazilians since da Silva's April 7 jailing on corruption and money laundering charges. He is appealing the conviction, but it could lead electoral courts to rule him ineligible for the ballot.

At least 30 per cent of those polled say they back da Silva to return to the office he held from 2003 to 2010. And if he cannot run, two-thirds of his potential supporters said they would vote for whoever he endorses.

In a race among 16 potential candidates, the poll showed Da Silva topped conservative lawmaker Jair Bolsonaro 30-15 per cent, with Marina Silva running third.

In another possible combination of candidates, da Silva topped Bolsonaro 31-17 per cent.

Da Silva's ratings dipped slightly from a January Datafolha poll when he was backed by 34 to 37 per cent. But it's not clear if that was due to his legal problems to or a different combination of rivals. Several contenders listed in that poll have dropped out or been added, making a direct comparison impossible.

Da Silva's Workers' Party has pledged to register him on the Aug.15 deadline, but current electoral law bars his candidacy.

In scenarios without the left-leaning leader, Bolsonaro and former Environment Minister Silva are roughly even, with about 17 to 15 points.

On Friday, Bolsonaro was charged with racism by Brazil's attorney general, but the poll was completed before the news broke.

The biggest mover in the new poll is former Justice Joaquim Barbosa, the first black member of the country's top court. The poll showed him with a least 8 per cent backing.

President Michel Temer, who says he is considering a run, never topped 2 per cent support in any scenario. His former Finance Minister Henrique Meirelles, seen as a favourite of businessmen, was backed by 1 per cent.

Carlos Melo, a political science professor at Insper University in Sao Paulo, said the new poll shows da Silva remains powerful, and even if he is barred from running, he could be a kingmaker from jail.

The poll also found that 54 per cent of Brazilians consider Da Silva's arrest to be fair, while 40 per cent disagree. Six per cent did not respond.

Silva was sentenced to 12 years and one month in prison, allegedly for accepting the promise of a beachfront apartment a kickback from construction company OAS.

A former CEO of the company testified under a plea bargain that the apartment was reserved for the former president, but da Silva says he never owned it or lived there and made one only visit to consider a business opportunity that didn't materialize.

Da Silva still faces seven other graft trials.

Datafolha interviewed 4.194 people between Wednesday and Friday. The margin of error is 2 percentage points.

News from © The Associated Press, 2018