SAO PAULO (Reuters) - The most likely political heir to jailed former President Luiz Inacio Lula da Silva insists the leftist leader is still the Workers Party’s candidate for the October elections, but he is preparing to step into the role.

Slideshow ( 4 images )

Fernando Haddad told Reuters on Tuesday that he was talking with other left-wing parties about forging a united leftist front for the elections if Lula is barred from running by a corruption conviction.

“We are seeing that both the left and the right are divided, with many candidates. With the exception of Lula, no one has more than 20 percent of voter support,” Haddad said in his first interview since Lula was imprisoned on April 7.

Haddad, 55, the former mayor of Brazil’s largest city, Sao Paulo, is the Workers Party’s “Plan B” in the likely case that Lula cannot run.

Sources in the party said Lula has privately discussed the need for Haddad to start preparing to run, even while the party plans to stick to their founder’s candidacy.

Lula has given his blessing to Haddad to be his emissary in talks with other leftist leaders. He said he had met with former Ceará state Governor Ciro Gomes and the head of the Brazilian Socialist Party, which may nominate Joaquim Barbosa, a former Supreme Court justice.

Both Gomes and Barbosa garnered 9 percent voter support in a Datafolha poll published on Sunday. Haddad polled 2 percent.

The Workers Party’s popularity has been damaged by corruption scandals and the impeachment of Lula’s successor, Dilma Rousseff, for breaking budget rules, ending its 14-year run in power.

Haddad thinks the party can still win 20 percent of the votes on Election Day. But with Lula excluded, the party might have to back a candidate from another party for the first time, especially in the likely scenario the top two finishers in a first-round vote head into a second-round ballot.

“There is no guarantee that the left will have a single candidate. But in the run-off, I’m sure we will unite behind one leftist candidate,” he said.

Haddad called for a center-left alliance to confront the equally fragmented center-right parties that have their own difficulties in a wide open field.

The challenge of the right is to field a candidate who can continue economic reforms while distancing himself from the unpopular incumbent President Michel Temer.

“Our challenge is simpler,” Haddad said. “We all oppose that agenda.”