JOHNSTON, Iowa —  Former GOP gubernatorial candidate Bob Vander Plaats on Thursday called on the remaining four Iowa Supreme Court justices who were involved in a controversial 2009 same-sex marriage ruling to resign their posts.

He suggested they use next month’s annual judiciary message to lawmakers to resign and establish an orderly process by which they can be replaced.

Vander Plaats, president of The FAMiLY Leader — formerly the Iowa Family Policy Center — urged the four justices to “do the right thing” by stepping down rather than face impeachment by state lawmakers.

He said impeaching them may be an option if they decline to take the signal from Iowans who voted against retaining Chief Justice Marsha Ternus and Associate Justices Michael Streit and David Baker in the Nov. 2 general election. The three defeated justices’ terms will end Dec. 31.

“We’re giving this court an opportunity to lead,” Vander Plaats said during the taping of an Iowa Public Television “Iowa Press” show slated to air Dec. 31.

He said the annual Condition of the Judiciary address to a joint convention of the Iowa Legislature on Jan. 12 would be the proper occasion for the court to announce the pending resignations of Justices Brent Appel, Mark Cady, Daryl Hecht and David Wiggins and a staggered timetable by which they would leave the bench.

“The condition of the judiciary is not very strong,” he said. “You saw that on Nov. 2. The people have lost complete confidence in them.”

Judicial Branch spokesman Steve Davis was unavailable for comment Thursday. The court has declined to comment on such matters in the past.

Vander Plaats, who led the successful campaign to oust three justices in last month’s election, said it would be “disingenuous” for the four justices who were not up for retention to ignore the will of the people by staying on until they face retention votes in future years. If they choose that course, however, he said lawmakers would have the choice to bring impeachment charges against them.

“I don’t think it’s in the best interest of the people of Iowa to go through a long, drawn-out impeachment hearing. There’s a lot of issues on the plate (next legislative session),” Vander Plaats said.

The possibility of a push in the legislature next year to try to impeach the remaining justices surfaced last week from several GOP lawmakers.

Vander Plaats said he believed articles of impeachment would be approved if the issue came before the Republican-led House and said there is a “better than 50-50 shot” the Senate — where Democrats hold a 26-24 edge — would vote to impeach the justices even though it requires a two-thirds majority.

Vander Plaats said he hoped the legislature would take action last session to reinstate the state law defining marriage as only between one man and one woman that was ruled unconstitutional by the unanimous court in April 2009. He said he believed the precedent has been set whereby the law could be re-passed with a provision that would limit judicial review.

He also favors the General Assembly giving voters the opportunity to adopt similar language to the state constitution and revamping the current judicial selection and retention process.

The group Justice not Politics, which formed in support of the three justices up for retention last month, issued a statement Thursday blasting Vander Plaats’ comments.

“Bob Vander Plaats’ call for the remaining justices to resign is just another example of the continued outrageous rhetoric and political grandstanding by him and his allies since the unfortunate loss of the three justices in the November election. Enough is enough. When Iowa voters rejected Bob Vander Plaats’ three bids for governor, he didn’t listen to the ‘will of the people’ and leave public life,” according to the group’s statement.

“A small handful of politicians do not have a mandate to decide the future of our courts for the people of this state. They are imposing their will on Iowans, usurping our constitutional right to a retention vote. This is complete hypocrisy given the platform of their ouster campaign,” the group said.