(Des Moines, IA) Republican president candidate Steve Forbes Saturday promised he’ll use a different style of campaign advertising, if competitor George W. Bush agrees to a series of six, one-on-one debates.

“I’ve made the offer that if we have these debates, these series of in-depth debates, in my ads I’ll only use material from those debates,” Forbes told reporters in a news conference in Des Moines.

In 1996, Forbes used a barrage of pointed ads to criticize front-runner Bob Dole. Dole has said those Forbes ads damaged his chances against Bill Clinton. Bush’s campaign has begun to prepare for a Forbes attack this time around.

“He has reason to be concerned (by) the fact that he hasn’t put forth real proposals, or what he has put forth simply gives more power to Washington,” Forbes said of those preparations.

So far this year, Forbes has run advertisements that tout his views on issues like social security and tax policy, as well as ads that feature his family.

“Those who fear this campaign must obviously fear substance,” Forbes said. “I don’t do personal attacks. I go for real issues and that’s what the whole basis of my campaign is.”

On Friday, Gary Bauer — another GOP candidate — said Forbes had “peaked” and couldn’t buy any more votes than he has already. Bauer proclaimed himself the “conservative alternative” to Bush. Forbes brushed off the Bauer comments.

“We’re gaining strength as we are speak,” Forbes said, citing a recent National Federation of Republican Assemblies straw poll that he won. “So I have become the conservative alternative to the front-runner and look forward to the showdown early next year.”

Forbes met with supporters and signed copies of his new book in Des Moines on Saturday before campaign appearances in three other Iowa cities.