Brazil heads to presidential vote with final polls too close to call

Brazilians will vote Sunday in the first round of a presidential election that final polls show is too close to call. President Luiz Inácio Lula da Silva faces Senator Flávio Bolsonaro, a close ally of President Donald Trump.

AtlasIntel's final pre-election survey put Lula at 46.2 percent of valid votes in the first round and Bolsonaro at 43.1 percent. The poll surveyed 5,005 voters from September 23 to 28 and showed a potential runoff tied at 50 percent each.

An outright victory requires more than 50 percent of valid votes, which exclude blank and spoiled ballots. If no candidate reaches that threshold Sunday, the top two finishers will meet in a second round on October 25.

Voting is mandatory for literate Brazilians between 18 and 70, with ballots cast on electronic machines nationwide. Voters will also choose all 513 members of the Chamber of Deputies, two-thirds of the Senate, governors and state legislators. Polls close at 5 p.m. Brasília time, or 4 p.m. Eastern time.