JACKSON - State Sen. Barbara Blackmon used a closed Kmart store in Jackson as a backdrop to challenge Lt. Gov. Amy Tuck on Friday to meet her in a debate on jobs and the economy.

Blackmon, the Democratic nominee for lieutenant governor, also condemned political ads that she said distorted her record on economic development. Blackmon decried what she called "the secret spending that has resulted in vicious, negative attack ads."

The ads were paid for by an organization called Progress America Group. According to Blackmon, the group has not registered with the Federal Election Commission.

David Blount, spokesman for the Mississippi Secretary of State's Office, said the group has not registered as a political action committee or filed any financial disclosures.

Blackmon called on Tuck to condemn the ad.

"The unfair attack by Amy Tuck and her big buck backers are occurring because I have the strongest economic development message in this campaign," Blackmon said before leaving a news conference without answering questions. "On Amy Tuck's watch, the state has lost 44,000 jobs and she has not spearheaded any major economic development effort."

Tuck was campaigning Friday in the Mississippi Delta and was not immediately available for comment. Tuck, as lieutenant governor, is a member of the Joint Legislative Budget Committee, which is working on a budget to present to lawmakers in January. Tuck is chairwoman of the committee this year.

Tuck campaign spokesman Michael Goode said Tuck knows nothing about Progress America Group. He said the political ad was an "independent expenditure."

"I saw one (the ad) for the first time on TV and I understand why Barbara is upset that someone is telling Mississippians about her radical record of supporting higher taxes," Goode said.

Tuck and Blackmon are scheduled to debate Oct. 30 on Mississippi ETV. A second debate is planned for WTOK-TV in Meridian, but a date has not been confirmed, said John Johnson, the station's news director.

Tuck and Blackmon have been bickering this week over abortion. Blackmon had asked Tuck to sign an affidavit attesting that the lieutenant governor had not had an abortion. Tuck said she would sign it.

Blackmon has criticized Tuck's leadership of the Mississippi Senate. Blackmon, a Canton lawyer, also introduced a jobs plan earlier this year that emphasized tax breaks and other incentives for small businesses.

Tuck said her opponent is against tort reform. Tuck said the state's current civil laws and multimillion-dollar verdicts are to blame for the flight of doctors who cannot afford medical malpractice insurance in Mississippi.