RICHMOND -- Democratic U.S. Senate candidate Mark Warner has refused an invitation from the League of Women Voters of Virginia to participate in a statewide televised debate with Republican rival Jim Gilmore but has not ruled out other debate offers.

The League of Women Voters had planned to sponsor a debate between the former governors that would be made available to television and radio stations throughout the state. Gilmore agreed to participate. Warner declined, according to organizers.

"We're very disappointed that we could not get both major senatorial candidates to agree to participate in a debate this year," said Olga Hernandez, president of the organization, in a statement. "We believe that televised debates are one of the most effective ways for voters to learn about the candidates and their positions."

The organization sponsored a televised debate in the 2006 Senate race between Democrat Jim Webb and Republican incumbent George Allen. The television feed was made available statewide and picked up by C-SPAN.

Hernandez said the League of Women Voters extended invitations to both candidates in June and asked them to respond by Aug. 25. Gilmore's campaign said organizers offered several dates for the candidates to consider. But Warner could not commit to a specific date by the organization's deadline, campaign spokesman Kevin Hall said.

"Governor Warner certainly respects the good work done by the League of Women Voters, and we regret that we were not able to commit to their proposal," Hall said. "We continue to evaluate other proposals."

Gilmore and Warner held one debate in July at The Homestead resort in Bath County, an event sponsored by the Virginia Bar Association. The two candidates also have committed to a Sept. 18 debate in Northern Virginia sponsored by the Fairfax County Chamber of Commerce.

The July debate was not broadcast statewide, and the September showdown is not expected to be. In addition to the scheduled debates, Warner has accepted invitations for three joint campaign appearances, Hall said.

Warner and Gilmore are competing for the Senate seat held by Republican John Warner, who will retire when his fifth term expires. Mark Warner, who is not related to the incumbent senator, succeeded Gilmore as governor in 2002.

Warner leads Gilmore in public opinion polls and has a substantial funding advantage as the race heads into its most critical stage. But Warner's rejection of the League of Women Voters debate had Gilmore accusing his Democratic rival of ducking a confrontation.

"Mark Warner apparently does not want the people of Virginia to have an opportunity to understand clearly where he stands on the issues," Gilmore said in a statement released by his campaign.

"I think the people have a right to ask: What is Mark Warner hiding?" Gilmore said. "As for me, I will debate him any time and any place because I believe the people of Virginia are entitled to that kind of public discussion."

Warner and Gilmore are scheduled to appear in Buena Vista on Monday to participate in the city's annual Labor Day parade.