A political campaign ad by Congressman Doug Lamborn’s has a bank co-founded by his Republican primary opponent, Robert Blaha, claiming the incumbent has broken the law.

At issue is whether Lamborn used falsehoods to undermine the bank. The ad, titled “Honor,” alleges that Integrity Bank and Trust, which Blaha helped start, is “currently rated below average.” But the Lamborn campaign’s basis for the claim, www.bankrate.com, said the bank “exhibited a generally satisfactory condition” at the beginning of the year.

Colorado statutes make it illegal to spread false information about banks that undermines consumer confidence, and Integrity claims Lamborn’s commercial could hurt its reputation. Integrity sent Lamborn a letter that cited Colorado law and said the campaign has committed a misdemeanor, which is punishable by up to a year in jail and a $1,000 fine.

Claims of falsehoods, even criminal ones, are common in campaign season, but seldom wind up going further.

Fourth Judicial District Attorney Dan May said Integrity or Blaha would have to file a complaint with his office or the state Attorney General for the case to be pursued.

“Our office isn’t looking at all the commercials and saying if they’re accurate or not,” May said.

If a formal complaint is filed with May’s office, he said he would forward it on to the District Attorney’s Council, since he has endorsed Lamborn in the past.

The two campaigns have dueled on the airwaves in recent weeks as Blaha seeks to unseat Lamborn in the June 26 GOP primary.

The ad in question is posted online, at www.theblaharecord.com, along with several other campaign TV spots from the Lamborn camp.

Integrity was fined by the FDIC, as Lamborn’s ad claims, but Blaha’s campaign says that was for filing an incorrect form. The bank’s performance is perfectly fine, Blaha said.

The bank is not pursuing charges at this point, according to the letter, written by attorney Daniel Crabtree of the Kansas City firm Stinson Morrison Hecker LLP. It didn’t expressly ask the campaign to remove the ad, but said it was merely bringing it to Lamborn’s attention.

“We trust that you will give this matter your immediate attention,” Crabtree wrote.

Crabtree declined to comment further on Friday.

Blaha, however, said Lamborn lied.

“His campaign is certainly based on something other than facts,” Blaha said. “It’s based on lies, half-truths and innuendo.”

Lamborn spokeswoman Catherine Mortensen said in an email that Blaha was trying to make something out of nothing.

“Mr. Blaha’s allegations are ridiculous,” Mortensen said. “They are what you would expect from a candidate who is increasingly desperate.”

Lamborn was unavailable Friday. The congressman’s father died this week, Mortensen said, and so the congressman is spending the weekend with family and at the funeral.

Read more about the CD 5 primary here.