OKLAHOMA CITY (AP) — The top two candidates running for the open 2nd Congressional District seat in eastern Oklahoma came under fire this week over their business experience in the private sector.

Democrat Rob Wallace on Friday criticized his Republican opponent Markwayne Mullin for not using the federal E-Verify system to check the immigration status of the workers at his company, Mullin Plumbing.

But Wallace himself was forced to fend off scrutiny over several failed business ventures after the Oklahoma Republican Party released an ad that was critical of his experience.

Wallace and Mullin are battling for Oklahoma’s sprawling 2nd Congressional District that stretches from the foothills of the Ozark Mountains in the northeast to the Red River border with Texas. The seat came open when current U.S. Rep. Dan Boren, the only Democrat in the state’s congressional delegation, announced last summer he wouldn’t seek a sixth term.

A former state and federal prosecutor, Wallace on Friday tried to paint Mullin as “weak on immigration” because Mullin has said on the campaign trail that he doesn’t use the free federal E-Verify online system.

“He’s not taking advantage of the tools to determine who is and who isn’t illegal, then that’s part of the problem,” Wallace said. “I believe it should be incumbent on those businesses to make sure the people they’re hiring are either citizens or are in the country legally.”

Mullin, of Westville, couldn’t be reached for comment on Friday, but his campaign issued a statement stating that all of Mullin’s employees are either American citizens or in the country legally.

“Anything said to the contrary is a flat-out lie from a desperate politician who will say anything to get elected so he can go support the Obama agenda,” Mullin campaign manager Tim Ross said in a statement.

Ross also took a shot at Wallace’s experience in the private sector, including his involvement with several failed business ventures from his time as an attorney in private practice.

“Rob Wallace has had failed business after failed business, lawsuit after lawsuit accusing him of defrauding investors,” Ross said. “The man even had his wages garnished to pay a judgment against him.

“Maybe he should start a company that actually creates jobs before he talks about how job creators run their companies.”

Wallace, of Fort Gibson, said that as an attorney in private practice in the 1990s, he was often the registered agent for companies and his name was on incorporating documents, but that he was not involved in the day-to-day management or operations of several failed companies.

Wallace acknowledged he was paid for his legal services with an ownership stake in the Scott Branch H.E.S. mining company in the early 1990s, and that his wages were garnished after the company’s primary owner defaulted on a lease for some mining equipment.

“He needed some help on an equipment lease. I foolishly co-signed an equipment lease with him,” Wallace said. “When his company failed, the lease company came after me.”

Wallace and Mullin will appear on the Nov. 6 general election ballot, along with independent Michael Fulks of Heavener.