King County Executive Ron Sims unleashed his first radio ad Wednesday against his challenger, David Irons, attacking the Metropolitan King County Council member's business record.

"When David Irons ran a business it went it into bankruptcy," the ad says. "Bankruptcy? ... Not exactly a success, was it?"

It then details how Sims cut the county budget when he faced a $137 million deficit and "turned it around — no bragging — no exaggerating — just hard work, straight talk, and the values we share."

Irons said the ad, which refers to his work at a local Internet company called Brigadoon.com, is inaccurate. He said he left before the company went under because he knew "it had a failed business practice."

The negative ad proves how tight the race has gotten, said Irons, who called Sims "desperate."

"We're almost in full mudslinging mode here," said Christian Sinderman, spokesman for Sims' campaign. "We'll get there by next week."

Irons joined Brigadoon.com in 1995 and worked there for two and a half years as chief operating officer before quitting and starting a new Internet company. Brigadoon.com filed for Chapter 7 bankruptcy in March 1998.

He said that the new company, CCPI, which provides telecommunications services for conventions, remains in business and is profitable. "I wasn't the founder in this one [Brigadoon.com]. I was one of the managers," Irons said. "There's a monumental difference in that."

Asked why Sims' ads pin the company bankruptcy on Irons, who no longer worked there, Sinderman said, "The fact that they didn't file their papers until after he left really makes it look worse for him. You can't bail off a sinking ship and then claim you were never on it."

The Irons campaign has been running four different radio ads.

In one ad, Iron says, "I have two successful small businesses which, along with my kids, has certainly taught me a lot. Ron Sims has never worked in the private sector. I think we're seeing the results of that."

In another spot Irons describes a growing "lack of faith" in Ron Sims.

John Wyble, a political consultant who primarily works with Democrats, said both campaigns are trying to define Irons.

"People have a very good understanding of who Ron is and I think they have no idea of who Irons is," Wyble said. "They are probably worried that David Irons is going to paint a very positive portrait of himself without anybody knowing the less-positive things."

TV ads for Irons campaign are expected to air soon.

Sinderman declined to describe Sims' future media strategy, saying only that "all options are on the table."

Sharon Pian Chan: 206-464-2958 or schan@seattletimes.com