RIO DE JANEIRO, Jan. 31 (Xinhua) -- Former Brazilian President Luiz Inacio Lula da Silva would lead the presidential election with 34 percent of voter intention, according to a Datafolha poll released Wednesday.

It was the first survey taken since Lula's conviction on corruption charges was upheld by an appeals court last week.

According to the poll, Lula would be ahead of other candidates in the first round if he can run, with extreme-right wing candidate Jair Bolsonaro getting 16 percent, followed by former senator and Environmental Minister Marina Silva at 8 percent.

In all five scenarios with him as one of the candidates, Lula has the lead by 18 points or more.

In scenarios without Lula, Bolsonaro has the lead. However, no candidate has more than 20 percent of voter intention.

The former president was sentenced to nine and a half years of prison last year and appealed the decision, but the appeals court upheld the previous decision and even increased Lula's sentence to 12 years of jail.

The Brazilian Supreme Court of Justice Tuesday rejected a motion by Lula's defense team to avoid his arrest for a graft conviction. The Electoral Court can therefore forbid his candidacy in the October election.