Brazil's Superior Electoral Court (TSE) on Thursday rejected a request to keep ex-president Luiz Inacio Lula da Silva out of opinion polls in the lead-up to October's presidential race.

Judge Tarcisio Viera de Carvalho Neto denied the motion, which asked for polling firms' removal of Lula's name from the roster of candidates until the TSE validates his candidacy.

The two-time president is currently serving a 12-year prison sentence for corruption, but the Workers' Party has nevertheless chosen him as its candidate.

As Brazil's Clean Record Act bars anyone with a conviction from running for elected office, the TSE is expected to make a decision on his eligibility to run.

The United Nations Human Rights Commission on Friday requested a guarantee of Lula's political rights, including access to the press and to members of his party.

Last Thursday, the court gave Lula seven days to argue his case for eligibility.

Opinion polls have consistently shown Lula leads the field of candidates, with some 38-percent support among the electorate.