Brazilian President Luiz Inácio Lula da Silva and Senator Flávio Bolsonaro are tied at 50 percent of valid votes, according to a poll by the Datafolha institute released today, three days before the runoff election.

Conducted between Tuesday and this Thursday, the survey reflects a change compared with other Datafolha measurements released after the first round of October 4.

In the first week of the runoff campaign, Flávio Bolsonaro had 52 percent of valid votes against Lula's 48; while in the following study, published on October 15, the difference had narrowed to 51 against 49.

The poll, which interviewed 2,520 people in 154 Brazilian municipalities, has a margin of error of two percentage points in either direction, so the result reflects a technical tie between the two candidates and does not constitute a definitive projection of the count.

In total voting intention, which includes blank and null ballots and undecided voters, the senator reaches 47 percent and the president obtains 46, while five percent declare they will vote blank or nullify their ballot, and two percent still do not know which option they will choose.

That indicator also showed modifications: in the previous measurement, Flávio Bolsonaro registered 47 percent and Lula 45, with six percent blank or null votes and two percent undecided.

The study also indicates that 94 out of 100 respondents say they have decided their vote. Among those who support Lula, the proportion rises to 96 percent, while among the senator's voters it reaches 95.

Despite the tie registered in voting intention, 53 percent of those consulted believe Flávio Bolsonaro will win the election, compared with 39 percent who bet on a victory for the current officeholder, and the remaining eight did not express an opinion on the matter.

By region, the senator maintains an advantage in the Southeast, the country's largest electoral college, with 51 percent of total voting intention against Lula's 41. He also registers his best result in the South, where he reaches 58 percent, against the president's 33.

Lula retains a wide advantage in the Northeast, with 65 percent against 30 for his adversary.

Among lower-income voters, the president obtains 54 percent and Flávio Bolsonaro adds 39.

The difference also favors the head of state among voters with lower educational levels, with 53 percent against 40, while among evangelicals the senator reaches 69 percent and Lula 26.

The runoff will be held this Sunday, October 25, after a first round in which Flávio Bolsonaro obtained 47.03 percentage points of valid votes and Lula 45.16, in the tightest contest since Brazil's return to democracy in 1985.