FILE PHOTO: A combination photo shows presidential candidates Jair Bolsonaro (L) in Brasilia, Brazil September 4, 2018 and Fernando Haddad in Curitiba, Brazil September 24, 2018. REUTERS/Adriano Machado/Rodolfo Buhrer/File Photos

BRASILIA (Reuters) - Brazil’s far-right presidential candidate Jair Bolsonaro has only a six-point lead over surging leftist Workers Party candidate Fernando Haddad, and would lose a second-round runoff against him next month, a new opinion poll showed on Wednesday.

Bolsonaro, who is recovering in hospital from a near-fatal stabbing, has held his lead ahead of the Oct. 7 election with 27 percent of voter support, the survey by polling firm Ibope said.

Haddad, who replaced jailed former president Luiz Inacio Lula da Silva on the Workers Party ticket, is close behind with 21 percent.

Haddad, a former Sao Paulo mayor, would defeat Bolsonaro by 42 per cent versus 38 percent in a likely second-round runoff required by Brazilian law if no candidate wins a majority, according to the survey, which confirmed other recent polls.

Ibope said support for center-left candidate Ciro Gomes is hovering in the 12-percent area, while business-friendly former Sao Paulo governor Geraldo Alckmin is stagnant at 8 percent.

Bolsonaro would lose the election if he had to face either Gomes or Alckmin in a runoff, the poll showed.

The poll commissioned by the CNI industry lobby surveyed 2,000 voters across Brazil on Sept. 22-24 and has a margin of error of two percentage points.