The Brazilian presidential elections have been a tense affair, with far-right leaning Mr Bolsonaro and his Social Liberal Party (PSL) securing 46.7 percent of the votes in a convincing first round victory on October 7.
The far-right leader, who has likened his campaign to that of US President Donald Trump, will again face left-wing Workers’ Party (PT) candidate Fernando Haddad in the second round of voting on October 28.
In the first round, Mr Haddad secured just 29 percent of the vote.
But a new poll conducted by the National Confederation of Transport shows Mr Bolsonaro could clinch a majority vote when he faces Mr Haddad on Sunday.
The poll, released on Monday, suggests Mr Bolsanaro will become the new president of Brazil with 57 percent of votes.
His victory would be compared to just 47 percent of votes for Mr Haddad in the final round of voting.
According to MDA, the survey demonstrated there could be a marginal error of 2.2 percentage points.
The study, conducted between 20 and 21 October, surveyed 2,002 voters from 137 municipalities of all regions of the country were interviewed.
The poll results also suggest Bolsonaro has a rejection rate of 42.7%, compared to 51.4% that is attributed to Mr Haddad.
In August, the PT runner Mr Haddad was considered the standard bearer for former president Luiz Inacio Lula da Silva, who was jailed for 12 years for corruption in 2011
The PT party struggled for voter confidence since former president Lula da Silva was jailed for accepting a bribe from construction firm OAS.
Thousands of Brazilians took to the streets on Saturday to protest or support one of the two presidential candidates.
On Saturday demonstrators gathered in several cities throughout Brazil calling for votes for PT candidate Haddad and protested against candidate Jair Bolsonaro.
The nationwide demonstrations, organised by several women’s movements, denounced Bolsonaro as a racist, homophobic and chauvinist. In Rio de Janeiro, a similar demonstration was held in Cinelandia, with demonstrators carrying signs stating: “We want a country for everyone”.
On Sunday Mr Bolsonaro’s supporters took to the streets. In yellow and green t-shirts thousands marched down São Paulo’s Avenida Paulista carrying Brazilian flags, posters with the sayings “PT Never Again” and “My (political) party is Brazil” and calling for the end of corruption.
“We do not want corruption any more, but rather representatives who work for Brazil and not for themselves,” said Adelaide Oliveira, one of the leaders of the Vem Pra Rua (Come to the Streets) movement in São Paulo.
Additional reporting by Maria Ortega.