Brasilia, August 4 (RHC)-- Brazil's former president Luiz Inacio Lula da Silva, a current political prisoner, is expected to secure his Workers Party's nomination this Saturday and continue to overshadow the rest of candidates in the country´s presidential race.

Sentenced without evidence to 12 years and a month in jail, within the questioned anti-corruption operation Lava Jato, led by federal judge Sergio Moro, Lula easily leads all intentional surveys of votes in the biggest South American country..

As confirmed Friday by PT´s national president,  Gleisi Hoffmann, it is still undefined who will join Lula on the ballot as the vice presidential candidate . That name will be disclosed only on the eve of the registration of the candidacy, that is, on August 14. Hoffmann said.

Saturday will see three big party conventions, two months before the first round of voting on October 7.

Centre-left campaigner Marina Silva will get the nomination of her Rede party in Brasilia. Also in the capital, former Sao Paulo governor Geraldo Alckmin will secure the nod from the center-right Brazilian Social Democratic Party, or PSDB.

Polls show him with nearly double the support of all other main candidates in a first round.