(CNN) - Days before the Senate votes on ending the filibuster against Chuck Hagel's nomination for defense secretary, GOP Sen. Lindsey Graham sent a letter to the former senator, demanding access to Hagel's Senate archives and requesting answers to more questions about his record.
"Given the threats we face in the world and the public confidence level needed to be an effective Secretary of Defense, I believe the airing of your views and record is critical to the confirmation process," Graham stated in the letter.
Read the letter here.
The controversy started earlier this week when a reporter from the conservative publication, the Weekly Standard, tried to access the documents but was rebuffed by administrators at the University of Nebraska, Omaha.
The documents were given to the school by Hagel, a Nebraskan who retired from the Senate in 2009 after two terms.
The archive is comprised of legislative papers, including speeches, memos, handwritten letters, photos and other correspondence Hagel accumulated during his 12 years in office, according to the school.
In a statement to CNN, a spokesman from the University of Nebraska, Omaha, said there is good reason to deny access to the papers.
"Once the archive is processed and indexed, according to the standards and best practices of the Society of American Archivists, they will be open to the public. Until that time, they are not open to the public. We are working toward the day when the archive is processed and available to researchers," Charles Reed, a media relations coordinator at the school, said.
But Graham, among other Republicans, is calling on Hagel to allow the university to grant access to his archives. He also wants access to the Washington Speakers Bureau for video of Hagel's speeches and demands answers to previous questions about his position on Israel.
The South Carolina senator has been a leading voice in the fight against Hagel's nomination, questioning some of his past positions and statements. He was one of 15 GOP senators who called on Obama to withdraw his nomination of Hagel in a letter Thursday. The Senate is scheduled to vote Tuesday on Hagel.
Graham said Sunday he received a letter from Hagel disavowing a statement from 2007 in which Hagel was described as saying the State Department was an "adjunct" to the Israeli government. The senator said he accepted Hagel's response, which said he did not recall making that statement and would "disavow" it.
"Well, if in fact that's true, that would end that matter," Graham said. "So, I'll just take him at his word unless something new comes along."
In the same interview on Fox News, Graham defended his relentless vetting of Hagel.
"We're doing our job to scrutinize, I think, one of the most unqualified, radical choices for secretary of defense in a very long time," Graham said.
- CNN's Mike Mount, Kevin Bohn, Gregory Wallace and Ashley Killough contributed to this report.