A week after the campaign was rocked by a censure vote and a blistering investigative report, Mayor Ken Cockayne and challenger Ellen Zoppo-Sassu are scheduled to face voters Monday night.
The forum at St. Paul Catholic High School's auditorium begins at 6 p.m.
Monday morning, organizers were expecting all candidates to attend - including the 12 vying for city council seats.
Forum sponsor Cindy Bombard, president of the Central Connecticut Chambers of Commerce, said nobody has canceled so far.
The candidates have faced each other twice in October: First at a meet-and-greet at the public library, and then again when they gave brief presentations at the senior center.
But the Monday night forum shapes up to be the most heavily attended and lively of the sessions. It is the only one where candidates will exchange answers to the same questions and then give rebuttals, making it as close to a direct debate as this election season will offer.
The mayoral campaign has been uncommonly brutal by Bristol standards, largely because of accusations against Cockayne, a two-term Republican incumbent.
The council censured him last week by a 5-0 vote after concluding he had sexually harassed council member Jodi Zils-Gagne and was dishonest in responding to an outside attorney investigating the matter.
Days later, the city publicly released the lengthy investigative report, which further fueled what had become a social media war between his supporters and critics.
On Friday, administrators of the popular "Bristol Talks" page on Facebook declared a weekend-long moratorium on political postings, saying they felt exhausted after policing a flood of insulting and demeaning comments.
The report concludes Cockayne showed a council member private and potentially embarrassing photos of Gagne and her husband. It also says he retaliated against her husband's online radio station because it invited Zoppo-Sassu on the air.
Cockayne has dismissed the controversy as partisan mudslinging even though the censure vote was supported by Republican council members Anthony D'Amato and David Mills. The Republican Town Committee this weekend issued a statement that didn't use Cockayne's name, but condemned "any form of sexual harassment or retaliation."
Gagne, an attorney, has come under fire over a lawsuit alleging that she mishandled a 91-year-old man's property while serving as his conservator. She blames publicity about the lawsuit on Cockayne's family and friends.
Lost amid the conflicts has been substantive discussion about school funding, downtown redevelopment, blight and other issues facing Bristol. The chamber's session is intended as a way for both candidates - and all 12 council candidates - to speak about those matters.