David Vitter and John Bel Edwards will go toe to toe Tuesday night in the first televised debate during their runoff election for governor, with clearly drawn battle lines.

All signs indicate that Sen. Vitter will focus on Rep. Edwards’ Democratic voting record during his eight years in the state House while Edwards will want to keep attention squarely faced on questions about Vitter’s character, including the prostitution scandal.

Louisiana Public Broadcasting will air the one-hour event live at 7 p.m. statewide.

Following the format from the 2003 runoff debate — the last time gubernatorial candidates went head-to-head — the two men will ask some questions directly of each other. It’s quite possible the candidates will be forced to go off script in a decisive fashion, as has happened in past LPB runoff debates.

“I believe the gloves will be off,” Edwards said in an interview. “It will be entertaining for a lot of folks.”

Polls released publicly give Edwards a nine- to 20-point advantage, a situation few people would have predicted six months ago when Vitter was the heavy favorite in conservative Louisiana. Time is beginning to run out for him now, if the polls are accurate.

“Vitter has to take it to the guy (Edwards) over his voting record,” said Roy Fletcher, a longtime campaign strategist who worked most recently for Scott Angelle, the third-place finisher in the primary. “He needs to focus on specific votes by Edwards. He needs to draw distinctions and say, ‘This guy’s a liberal. I’m a conservative.’ ”

Turning to Edwards’ strategy, Fletcher said, “John Bel should try to stay above him, saying something like, ‘Gee, David, you really don’t have any character to run on. The only thing you can do is throw mud.’

“David Vitter will be fighting for his political life. That’s what makes it so compelling to me.”

Angelle has not endorsed either candidate, while Lt. Gov. Jay Dardenne, who finished fourth, endorsed Edwards last week. Combined, the two Republicans received 34 percent of the primary vote. Analysts estimate that Vitter needs 80 percent of their votes, but appears to be far short of that at this point.

Edwards said he expects Vitter to be on the attack from the outset.

“I believe my opponent is very desperate,” Edwards said. “He’ll say and do anything. I have no reason to think it wouldn’t be otherwise in the debate. It’s just his nature. It’s just who he is and what he is.”

Vitter was not available for comment. His spokesman, Luke Bolar, said of Edwards: “He will do anything to not have to talk about the issues. People will see his real liberal voting record.”

Both men were expected to spend Tuesday closeted with aides, reviewing issues and potential questions and preparing responses that will highlight their political advantages.

Edwards participated in all seven televised debates during the primary while Vitter attended only two, citing Senate business for most of his absences.

“They won’t ask any questions we haven’t already been asked,” Edwards said. “I’ll review notes from previous debate sessions. The difference is there will be only two of us.”

To keep his lead, “John Bel has got to further expand on his life experiences and his record, his time at West Point, in the military and in the Legislature,” said Ryan Cross, who was Angelle’s campaign manager. “He has to give Republican voters a reason to vote for him. The campaign is centered on swaying independents and Republicans who are softly committed to Edwards. That’s why a Democrat in a red state has a chance.”

One way for Edwards to appeal directly to those voters, Cross said, is to highlight his anti-abortion record and his background as a hunter who respects the rights of gun enthusiasts.

Vitter, Cross added, “has to show a soft side” to address concerns that he is divisive and overly negative. “That aggressive style is partly why Rep. Edwards is the front-runner. Vitter needs to highlight the policy differences.”

Cross added that the Vitter campaign is undoubtedly examining polling data to determine whether tying Edwards to President Barack Obama is peeling off white voters.

A sign that it isn’t came during a campaign forum Monday sponsored by the Press Club of Baton Rouge. Vitter mentioned Obama no more than one or two times.

Monday’s event gave a preview of the televised debate.

Vitter repeatedly said that Edwards’ voting scores with two business groups — 29 percent with the Louisiana Association of Business and Industry and 32 percent with the National Federation of Independent Business — show that he is too liberal for Louisiana.

Vitter meanwhile, scored 95 percent with LABI when he was in the state House from 1992-99 and 98 percent from NFIB during his 16 years in Washington.

Vitter noted that Edwards’ 29 percent meant he scored lower with LABI than did several other prominent Democrats during their years in the state Legislature: Mary Landrieu, 40 percent; Mitch Landrieu, 36 percent; and William Jefferson, 38 percent.

“If they are all moderates and conservatives, then John Bel is right,” Vitter said. “If Mary Landrieu, Mitch Landrieu and Bill Jefferson are not moderates or conservatives, then I’m right.”

Edwards said he has had a centrist record, helping to secure more dollars for public education in 2013 by forging a coalition with the conservative Fiscal Hawks in the House. He pledged to run a bipartisan administration.

“My record is squarely in the center of the political spectrum,” Edwards said.

LPB debates have proven to be decisive in past runoffs.

In 1991, then-state Rep. David Duke entered the debate with the momentum against Edwin Edwards but fumbled his responses during a tense stand-off over race with Norman Robinson, the black anchor with WDSU-TV in New Orleans.

Edwards finished off Duke during his closing statement, telling voters “don’t let him divide us. Don’t let him separate us from the rest of the nation. Don’t let him make a mockery of Louisiana. We’re too important.”

Edwards went on to crush Duke, 61 percent to 39 percent.

Follow Tyler Bridges on Twitter, @TegBridges. For more coverage of the governor’s race, follow Louisiana Politics at http://blogs.the advocate.com/politicsblog/.