IOWA CITY, Iowa (AP) — Gov. Terry Branstad on Monday called on the Iowa Board of Regents to delay consideration of a proposed public policy center honoring U.S. Sen. Tom Harkin at Iowa State University, saying approval should not be granted before three of his appointees join the board.

The nine-member board, which includes Harkin's wife and three others who have donated to his campaigns, is expected to consider approving the Harkin Institute for Public Policy during a meeting in Ames on Wednesday. The institute would store Harkin's papers from his long career, study policy matters related to the Democrat's legislative agenda and research the first-in-the-nation Iowa caucuses.

Detailed plans for the institute were released Thursday along with hundreds of pages related to regents' agenda materials. ISU Provost Elizabeth Hoffmann told The Associated Press the school started discussing the idea with Harkin and his wife last year at the urging of retired ambassador and Democratic Party official Charles Manatt.

She said Harkin's supporters were leading fundraising efforts for the center and were aiming for a $10 million endowment to support its annual operating budget, with initial gifts of $3 million already secured. She said the names of donors would be made public unless they request anonymity but she did not know the pledges' identities.

On Friday, Republican state Sen. Sandra Greiner of Keota sent a letter questioning whether the center would give Harkin an unfair political advantage while he's still in office and whether individuals and corporations who do business with the Senate would fund the center. She criticized "the secretive and rushed behavior" surrounding the proposal and asked for it to be delayed.

Branstad, a Republican, told reporters at his weekly news conference in Des Moines on Monday that he first learned of the proposal over the weekend. He said he believes the regents should delay approval of the center until three of his appointees who were confirmed by the Senate this month join the board May 1. The first meeting involving those three appointees — energy executive Bruce Rastetter, school superintendent Katie Mulholland and school board president Nicole Carroll — will be in June.

"He believes this should not be rushed," Branstad spokesman Tim Albrecht said. "As the new Board of Regents will be overseeing this project, they should give it due process."

Branstad's appointees will replace Regents Michael Gartner, Bonnie Campbell and Rose Vasquez on the board, which governs Iowa's three public universities.

Gartner, the Iowa Cubs president who has donated $8,600 to Harkin's campaigns since 2002, last week called the proposed institute a wonderful idea that would serve the public for generations. Campbell, an attorney who has donated $3,400 to Harkin since 2007, did not immediately return a phone message.

Campaign finance records also show Board President David Miles, a West Des Moines businessman who supports Democratic Party causes, has given $5,600 to Harkin's campaign since 2007.

Hoffman told AP last week that she has had conversations with both Tom and Ruth Harkin, a businesswoman appointed and reappointed to the board by Democratic governors, about the plan over the last year. But both Harkins have been mostly silent on the proposal since it was unveiled last week.

Ruth Harkin, whose term on the board expires in 2015, has not responded to several inquiries about her involvement in the project and whether she plans to recuse herself from considering it. Tom Harkin, who has represented Iowa in the U.S. House and Senate since 1974, has not granted interviews and has only said through a spokeswoman that he was honored by the proposal.

Harkin attended Iowa State on a Navy ROTC scholarship and graduated in 1962. Chairman of the powerful Senate Health, Education, Labor and Pensions Committee, Harkin has helped secure millions of dollars for school projects over the years.

School plans say the institute would house Harkin's memorabilia and print and digital materials that would be of interest to scholars from around the world and try to establish itself as a leading source for research and expertise on the Iowa caucuses.

In addition, the institute would hire professors and graduate students as Harkin fellows who would study "key areas that reflect Sen. Harkin's policy priorities" and are in line with the university's strategic plan, including agriculture, education, international development and domestic social welfare.