Brazil poll shows far-right Bolsonaro beating leftist in run-off (UPDATE 1)

Brazil's far-right presidential candidate Jair Bolsonaro is polling ahead of leftist Workers Party rival Fernando Haddad for the expected runoff in this month's election, a Datafolha opinion poll showed on Tuesday.

In a simulated second-round vote, the poll found Bolsonaro would get 44 per cent support, beating Haddad's 42 per cent, within the margin of error of the survey. The remaining 14 per cent of voters are undecided or plan a blank or spoiled ballot for the vote, which is compulsory.

If no candidate wins a majority in the first round on Sunday, the election will be decided in a second-round run-off on Oct. 28 between the two top vote-getters.

In the first-round scenario, Datafolha found that Bolsonaro had 32 per cent voter approval, four percentage points higher than the previous Datafolha poll on Sept 28. Haddad dropped one point to 21 per cent.

That raises the possibility of Bolsonaro rapidly gaining steam ahead of Sunday's vote - and possibly winning the election outright by taking a majority of the ballots.

In 2014, about a quarter of the electorate did not decide on a candidate until the final days ahead of the vote.

Datafolha's poll confirmed an Ibope survey released on Monday that showed Bolsonaro's advance since last week.

Datafolha surveyed 3,240 voters across Brazil on Monday and Tuesday. The poll's margin of error is 2 percentage points.