The most recent electoral polls in Brazil's presidential race, conducted only a day ahead of the casting of ballots, indicate that former leftist president Luiz Inácio Lula da Silva may win the election outright in the first round.

Lula received 50% of all votes considered valid, excluding blank and invalid ballots, according to pollster Datafolha, while right-wing incumbent President Jair Bolsonaro received 36%. To avoid a runoff, a contender needs more than 50% of the vote.

With 12,800 Brazilians being interviewed personally across 310 cities, this poll was the largest conducted by Datafolha. It has a 95% confidence level.

Another highly awaited poll, Ipec, was issued on Saturday. It showed Bolsonaro with 37% of the valid votes and Lula with 51%, strengthening the former president's chances of winning by a wide margin. 3,008 persons in 183 cities were polled by Ipec.

The leader of the worker's party is in a good position to win the election today without the necessity for a runoff, even if both surveys have a margin of error of plus or minus 2 percentage points. A runoff will be held on October 30 if none of the candidates surpasses the 50% threshold.

However, a poll conducted in the evening by pollster Quaest showed Bolsonaro with 38% of the valid vote, barely above the threshold, and Lula with 49%, just below it. Genial, a trading company, ordered the Quaest survey.

Bolsonaro has struggled to close the gap as Lula's voter support has wavered around the 50% mark over the past month.

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Lula was projected to receive 54% of the vote in the second round, 16 points more than Bolsonaro's 38%, according to Datafolha. Lula has a double-digit advantage according to Ipec, who has him at 52% to Bolsonaro's 37%.

The head of Brazil's Superior Election Court, Justice Alexandre de Moraes, spoke on a national broadcast to defend not only the electoral system but also democracy in the aftermath of recent attempts to repeatedly undermine the credibility the confidence of Brazil's computerized voting system which Bolsonaro has been attempting to discredit in the past few weeks.

“Democracy is a collective construction of those who believe in freedom,” de Moraes said. “The Brazilian Electoral Justice reaffirms its role as an instrument for the safe and transparent exercise of democratic choices made by Brazilians, in respect of the sovereign popular will.” 

In one of the most contentious and divisive elections in recent Brazilian history, voters will choose their next president on October 2.