A Des Moines attorney is challenging the ability of three members of a state judicial nominating commission to continue their terms into the new year, just as the commission is set to fill vacancies for the Iowa Supreme Court and Court of Appeals.

Bill Gustoff, in a letter sent Monday to State Court Administrator Todd Nuccio, argues that, despite debate surrounding a pair of conflicting state laws, the terms of commissioners Connie Diekema of Des Moines, Martin Diaz of Swisher and Suzan Boden of Sioux City should expire on Dec. 31.

Gustoff is the treasurer of the Republican Party of Iowa, a member of the state party's central committee and the former law partner of acting U.S. Attorney General Matt Whitaker.

He said his letter was not motivated by politics and he believes the judicial branch can act to hold elections and fill the positions by the time the commission takes up the vacancies created by outgoing Iowa Supreme Court Justice Daryl Hecht and Court of Appeals Chief Judge David Danilson.

"That's not my motivation here, because I think the Supreme Court can fix this and have a full slate of commissioners," Gustoff said Wednesday.

Diekema, Diaz and Boden are attorneys who were elected from among Iowa lawyers by the Iowa State Bar Association to serve one six-year term on the state judicial nominating commission, which sends the names of judicial finalists to the governor for final consideration.

The commission has 17 members, including eight elected lawyers and eight non-lawyers appointed by Republican Gov. Kim Reynolds. Iowa Supreme Court Justice David Wiggins chairs the commission.

Gustoff said he doesn't know the commissioners whose terms are expiring and said he is not aware of their politics.

"When I say I want to minimize the impact of politics on the court system, I mean it," he said.

Gustoff said he believes the Iowa Constitution is clear that commissioners' terms can't extend beyond six years. If the Attorney General's office says differently, he says he'd consider challenging that determination in court.

"I haven’t decided whether I’ll file a lawsuit or not, but I’ll certainly entertain the idea," he said.

A longstanding state law says the attorney members of the commission serve six-year terms that begin July 1 after elections are held in January. The Iowa Judicial Branch continues to follow that practice and holds the three commissioners' terms should expire June 30, 2019. The commissioners have been planning to participate in interviewing candidates and selecting finalists for the looming vacancies.

In his letter, Gustoff argues that their terms actually expire Jan. 1 due to a conflicting law approved in 2008. That law changed the makeup of the commission to comply with upcoming redistricting and declared all existing terms would end Dec. 31, 2012. Diekema, Diaz and Boden's terms began on Jan. 1, 2013.

Gustoff said Nuccio, the State Court Administrator, told him he would respond to his letter by Friday.

Steve Davis, a spokesperson for the judicial branch, said Gustoff's letter had been forwarded to the Iowa Attorney General's Office for a response.

Lynn Hicks, a spokesperson for the Attorney General's office, said the office's staff will respond to the judicial branch's request for clarity on the issue by Friday.

Hecht is leaving the Iowa Supreme Court next week, after announcing last month he would resign in order to focus on battling skin cancer. Danilson has announced that he would retire effective Jan. 4. Both were appointed by Democratic governors, and their departures give Reynolds further opportunities to move Iowa's judiciary in a more conservative direction.

The Iowa Supreme Court vacancy will be closely watched. Last year, the court ruled 5-2 that the Iowa Constitution protects abortion rights, striking down a 72-hour waiting period. But it may get the chance to revisit the issue soon in the form of a challenge to a law prohibiting abortions once a fetal heartbeat is detected.

Reynolds, who opposes abortion, signed the fetal heartbeat law this year, although it is on hold pending a legal challenge. She has already replaced one justice in the majority of the waiting period case. Hecht will be the second.

The Associated Press contributed to this story.