ABILENE, Texas -

Millions of dollars have been spent on negative campaign ads -- and the Republican U.S. Senate candidates are going head-to-head.

Ted Cruz and Lt. Governor David Dewhurst are in a runoff in just 12 days and the gloves are off.

Cruz is upset about what he calls negative campaigning. Dewhurst said his adds aren't negative -- they're stating the truth.

"You know, it is unfortunate that my opponent has chosen to put over $16 million of his own personal fortune into flooding the airwaves over false nasty attack ads," Cruz said.

Cruz said these ads are "falsehoods" and his campaign ads from day one have been about the issues that need to be faced in Washington.

"You know, Texans are getting tired of it, you know, it says something about someone who's been in an elected office for 15 years when they don't have anything positive to say," Cruz said.

On Thursday, a day after Cruz visited Abilene, KTXS asked Dewhurst what his thoughts were on the campaign ads.

"I don't run negative ads," Dewhurst said. "I run ads in which we are giving voters true information, correct information and let them make their own mind."

Cruz's commercials claim Dewhurst supported a payroll tax and he isn't conservative when it comes to spending.

"I've been literally facing a tsunami of untrue statements distorting the record of Texas and distorting the record of Governor Perry," Dewhurst said.

Ted Cruz has never held an elected position, which he touts. David Dewhurst has been the Lt. Governor of Texas since 2003.

Texans will head to the polls July 31 to vote in the runoff election. Early voting begins Monday, July 23.

By the way, our interview with Ted Cruz was in person when he came to Abilene-- we extended the same offer to David Dewhurst;. He was only able to interview with us by phone.