A top leader of Brazil's leftist Workers' Party on Tuesday criticized defeated first-round rivals for apparently not joining forces against the far-right front-runner in the country's presidential runoff election.

Chairwoman Gleisi Hoffmann took to Twitter after a poll released Monday showed congressman Jair Bolsonaro far ahead of her party's candidate, Fernando Haddad.

The move was the latest to suggest Haddad's camp has failed to attract presidential candidates defeated in the first round of voting to campaign in what the Workers' Party calls a "democratic front" against Bolsonaro in the second round runoff.

In this Sunday, Oct. 7, 2018 photo, presidential frontrunner Jair Bolsonaro flashes victory hand signs to supporters after voting at a polling station in Rio de Janeiro, Brazil. Bolsonaro just missed outright victory in Sunday's vote, and will face former Sao Paulo Mayor Fernando Haddad of the leftist Workers' Party in an Oct. 28 runoff. (AP PhotoLeo Correa)

In this Sunday, Oct. 7, 2018 photo, presidential frontrunner Jair Bolsonaro flashes victory hand signs to supporters after voting at a polling station in Rio de Janeiro, Brazil. Bolsonaro just missed outright victory in Sunday's vote, and will face former Sao Paulo Mayor Fernando Haddad of the leftist Workers' Party in an Oct. 28 runoff. (AP PhotoLeo Correa)

"If the Workers' Party were not in the runoff, it would endorse the adversary of congressman Bolsonaro because he will not promote democracy in this country," Hoffmann wrote. "We hoped that this was going to be a natural move (to endorse Haddad), but I am seeing it is not."

"In the future history will judge us all," the party executive said.

A former army captain, Bolsonaro has repeatedly defended Brazil's 1964-1985 military dictatorship. His running mate, Gen. Hamilton Mourao, has openly talked about a "self-coup" and organizing a constitutional assembly made of unelected representatives.

Bolsonaro won the first round of voting on Oct. 7 with 46 percent against Haddad's 29 percent. The Ibope poll released Monday night showed the far-right candidate's support at 59 percent ahead of the Oct. 28 runoff.

The cracks in Haddad's support were evident Monday, when a video surfaced of Senator-elect Cid Gomes criticizing the Workers' Party. He is the brother of defeated left-leaning presidential candidate Ciro Gomes, who garnished 12 percent of the vote in the first round.

"Lula is in jail, you idiot," Cid Gomes said while speaking to Workers' Party supporters at a rally, in a reference to jailed former President Luiz Inacio Lula da Silva. "You are going to lose, and you are going to lose ugly."

Bolsonaro's campaign aired the Cid Gomes video on TV on Tuesday.

Haddad did not hit back in a radio interview and said the Gomes brothers "know the risk that Bolsonaro represents to Brazil."

The Workers' Party candidate also tried to lure centrist Marina Silva and right-leaning Geraldo Alckmin, but both declared they were not endorsing any candidate for the run-off.

Haddad has so far been similarly rebuffed by former President Fernando Henrique Cardoso, who Bolsonaro once said he would like to see killed. But Cardoso has remained reticent about endorsing his left-leaning friend and fellow university professor.

The only defeated presidential candidate who endorsed Haddad was leftist Guilherme Boulos, who had minimal support in the vote.