In a few days, the two major-party candidates for governor in Virginia will walk onto a stage for one last debate -- but only if a bevy of lawyers, political operatives, television producers and the state's best-known pundit stop arguing about the rules.

Republican Jerry W. Kilgore and Democrat Timothy M. Kaine are scheduled to meet at 7 p.m. Sunday in a Richmond TV studio for a statewide televised face-off. It will be moderated by Larry J. Sabato, a University of Virginia professor, and promises to be the highlight of the fall campaign.

But it might not happen.

For days, both camps have been wrangling over the rules for the hour-long exchange. The main point of contention: whether the Kilgore and Kaine advertising gurus should be allowed to weave unflattering images and sound bites from the debate into potentially devastating TV spots.

Kaine says yes. Kilgore says no.

An e-mail exchange between Kilgore campaign manager Ken Hutcheson and Kaine communications director Mo Elleithee gives a sense of the posturing.

"When are you and [Sabato] free to get together to sign a no-use agreement for the Oct. 9 debate?" Hutcheson wrote to Elleithee on Sept. 30.

"As you know, there is no 'no-use agreement' for this debate, nor does the Kaine campaign have any interest in signing one," Elleithee wrote back.

Legal agreements prohibiting the use of debate footage in campaign commercials are common. They are, in a sense, a mutual destruction-avoidance system for candidates. No one wants a gaffe or bad answer repeated again and again in an opponent's ad.

They've been part of almost every modern Virginia debate, observers say.

Until Tuesday, sponsors of Sunday's debate -- NBC affiliate WWBT-TV (Channel 12) in Richmond and Sabato's Center for Politics -- had stayed out of the fray.

But in a letter to both campaigns, the TV station's vice president, Nancy Kent Smith, wrote that the station's lawyers consider the debate copyrighted material and "will not permit any candidate or campaign-related organization to use footage, audio, or still images from the debate in campaign-related activities, including commercials and websites."

That wasn't enough for the Kilgore camp, which kept pushing for a legally binding agreement. In an e-mail, Hutcheson pointed out that Elleithee, as spokesman for then-candidate Mark R. Warner in 2001, had insisted on one.

"It becomes clear that non-use agreements are commonplace and part of the routine apparatus of debate agreements," Hutcheson wrote.

"Any deviation from this tradition . . . can only be seen as a desperate attempt to preserve campaign debates as a political issue."

Sabato, who has moderated many Virginia debates, weighed in Tuesday on behalf of Kilgore -- and in an attempt to save the debate.

"I trust you both, but to avoid further misunderstanding, we will bring a document on Thursday for representatives of both campaigns to sign," Sabato wrote to Elleithee and Hutcheson.

Later, in a public statement, Sabato revealed exasperation, saying, "It would be a terrible shame if the campaigns' bickering over a single rule resulted in the cancellation of the only statewide TV debate in this election season." So what will happen?

On Aug. 10, Kaine's campaign said it would accept the Sabato-WWBT debate unconditionally.

In a release, Elleithee wrote, "We are also fully accepting the rules, logistics and format as determined by the debate sponsors."

That would seem to include the rules regarding a no-use agreement. But late Tuesday, Kaine campaign manager Mike Henry released a letter to Sabato saying his camp was considering whether to sign the agreement.

It said Kaine intends to be at the debate one way or the other.

"We will follow the copyright law, and all other laws, with respect to debate footage," Henry said.

"However, this sole statewide televised debate belongs to Virginia's voters as much as it does to any private interests."

Democrat Timothy M. Kaine, right, and Republican Jerry W. Kilgore are to debate Sunday -- if they can agree on one remaining technical issue, whether TV footage can be reused in their ads.