The GOP race in Iowa’s 4th District will be “very nasty,” U.S. Rep. Steve King said Saturday, singling out a prominent GOP operative in Iowa and mega-GOP donor Bruce Rastetter as the two fueling the primary challenge from state Sen. Rick Bertrand.

Bertrand, R-Sioux City, announced March 17 that he would challenge King for the GOP nomination, where the winner will likely win the general election in the heavily Republican district.

Nick Ryan, GOP operative with a long history in Iowa politics, and Rastetter, a wealthy agribusiness leader from the 4th District who has given money to Republicans in the state, are the two main individuals who convinced Bertrand to run against King, King said in a phone interview Saturday with the Iowa State Daily.

“They want to buy a congressman,” King said.

King said he has had conversations with others who called him to say they were recruited to run for the seat, and they were offered hard money for their campaign and PAC money for a “scorched earth” campaign against him. He declined to give any specific names on who called him.

King said it will be up to Bertrand to answer questions on if he was actually offered anything to run for the seat.

“He will be obligated to answer the question, ‘What were you offered, and what did you accept?’” King said. “He has not answered that question, and I know what others were offered — I received their phone calls, and I take them at their word.”

When asked Saturday if the primary race would be “nasty,” King said it would indeed be “very nasty” while going after Ryan.

“I think it’ll be a very nasty primary,” King said. “That’s the stock and trade of Nick Ryan. He doesn’t know anything else, and he profits from money raised and money spent, so he gets a commission coming and going. He needed someone to attack in a primary or else his revenue stream would probably be a little short until the general election.”

Ryan said in an email to The Daily on Saturday that he has no formal role in Bertrand’s campaign, but offered a statement on King’s comments.

“How disappointing and sad that Steve lashes out like this,” Ryan wrote. “I want a congressman that is positive, forward looking and puts his district first — not one that attacks his own constituents. In fact, I’ve never seen a congressman do that in either party. We can do better here in the Fourth District and that’s why I will be voting for change and supporting Rick Bertrand.”

He also said King has personally asked him to raise money in the past.

“Steve has called me many times and asked for money,” Ryan said. “[He] came to my office and wanted money. Wanted me to get others to give him money. And now he’s just turned into this insult-driven person. I think Washington has gotten to him.”

Rastetter told The Des Moines Register last week that he would not be backing Bertrand if he did not think he could win. He also said on this weekend’s edition of Iowa Press, which first aired Friday on statewide Iowa Public Television, that King has not done enough for constituents in Iowa.

“I think the district needs a congressman that represents all constituents,” Rastetter said. “I think Steve [King] has represented a variety of national issues rather than being a congressman who is intent on solving constituent problems, constituent issues and issues that are important to the district, like we saw with ethanol in the caucuses.”

Rastetter, who is also president of the Board of Regents, denied he “recruited” Bertrand to run, instead saying on Iowa Press that Bertrand said he was interested, and Rastetter “encouraged” him to join the race.

Rastetter declined to comment further to The Daily on Saturday night.

Bertrand, in a sit-down interview with The Daily on Tuesday, said King instantly took a ‘how dare you?’ attitude when he entered the race instead of putting forward a vision for Iowa.

“I think he made that up,” King said. “There is nothing I said that he can point to that would indicate that. I was struck by the fact that he didn’t have a single issue to utter in his announcement, and to this point he hasn’t uttered a single issue yet. I will point to my record and let [voters] know that [in Congress] I’ve given my word, I’ve kept my word and they can always take my word to the bank.”

Iowa Republicans will vote in the primary election June 7.