Fifteen Republican senators sent a letter to the White House Thursday, urging President Barack Obama to withdraw the nomination of former Sen. Chuck Hagel (R-Neb.) for secretary of defense and going as far as stating that a nominee would require 89 votes for confirmation.
The letter was signed by Senate Minority Whip John Cornyn (R-Texas), along with other notable senators including Lindsay Graham (R-S.C.), Ted Cruz (R-Texas), Marco Rubio (R-Fla.) and Jim Inhofe (R-Okla.)
In the letter, the senators call for the president to withdraw the nomination because Hagel does not have "the broad base of bipartisan support and confidence needed to serve efficiently."
The letter came after a key Republican senator, Sen. Richard Shelby (Ala.), announced that he plans to vote for Hagel, making him the third GOP member to announce he would do so.
Notably, Republican Sens. John McCain (Ariz.) and Kelly Ayotte (N.H.), who have both opposed Hagel, did not add their names to the letter.
The letter claims that historically, no secretary of defense nominee has been confirmed with more than 11 opposing votes and calls for a less "controversial" and "divisive" candidate. However, presidential nominations have only required 50 votes for confirmation, and filibustering one, as has happened with the Hagel nomination, is unprecedented.
Despite the move, Republicans have signaled more willingness to consider the Hagel nomination for a full vote after the President's Day Recess.
Read the full letter below:
STAYING: Joe Biden, Vice President
U.S. Vice President Joseph R. Biden speaks during an inauguration reception at the National Building Museum January 20, 2013 in Washington, DC. (BRENDAN SMIALOWSKI/AFP/Getty Images)
STAYING: Tom Vilsack, Secretary Of Agriculture
U.S. Secretary of Agriculture Tom Vilsack speaks during day two of the Democratic National Convention at Time Warner Cable Arena on September 5, 2012 in Charlotte, North Carolina. (Photo by Alex Wong/Getty Images)
LEAVING: Rebecca Blank, Acting Secretary Of Commerce
Acting United States Commerce Secretary Rebecca Blank smiles at a news conference for the opening of the U.S. Patent and Trademark Office's first satellite location in Detroit, Friday, July 13, 2012. No full replacement has been made since John Bryson's June 2012 resignation. (AP Photo/Paul Sancya)
LEAVING: Leon Panetta, Secretary Of Defense
US Defense Secretary Leon Panetta talks next to British Defense Secretary Philip Hammond (unseen) during a joint press conference in Lancaster House, central London, on January 19, 2013. (LEON NEAL/AFP/Getty Images)
STAYING: Arne Duncan, Secretary Of Education
U.S. Secretary of Education Arne Duncan announces that Miami-Dade County Public Schools won the 2012 Broad Prize for Urban Education on October 23, 2012 in New York City. (Photo by John Moore/Getty Images)
LEAVING: Steven Chu, Secretary Of Energy
U.S. Secretary of Energy Steven Chu speaks during a press conference at the 2012 Seoul Nuclear Security Summit at the Coex Center in Seoul on March 26, 2012. (NICOLAS ASFOURI/AFP/Getty Images)
STAYING: Eric Holder, Attorney General
U.S. Attorney General Eric Holder speaks during a news conference at the Justice Department, on December 19, 2012 in Washington, D.C. (Photo by Drew Angerer/Getty Images)
STAYING: Kathleen Sebelius, Health And Human Services Secretary
Secretary of Health and Human Services Kathleen Sebelius speaks during day one of the Democratic National Convention at Time Warner Cable Arena on September 4, 2012 in Charlotte, North Carolina. (Photo by Alex Wong/Getty Images)
STAYING: Janet Napolitano, Secretary Of Homeland Security
Homeland Security Secretary Janet Napolitano speaks during a ceremony honoring Senate Homeland Security and Governmental Affairs Committee Chairman Sen. Joseph Leiberman (I-CT) at the at the U.S. Citizenship and Immigration Services December 19, 2012 in Washington, D.C. (Photo by Chip Somodevilla/Getty Images)
STAYING: Shaun Donovan, Secretary Of Housing And Urban Development
HUD Secretary Shaun Donovan, speaks about distressed home owners during a news conference at the Justice Department, on October 9, 2012 in Washington, DC. (Photo by Mark Wilson/Getty Images)
LEAVING: Ken Salazar, Secretary Of The Interior
Interior Secretary Ken Salazar speaks during a tourism and conservation discussion with the Greater Miami Chamber of Commerce on January 11, 2013 in Miami, Florida. (Photo by Joe Raedle/Getty Images)
LEAVING: Hilda Solis, Secretary Of Labor
U.S. Department of Labor Secretary Hilda Solis speaks during a Urban Economic Forum co-hosted by White House Business Council and U.S. Small Business Administration at Loyola Marymount University on March 22, 2012 in Los Angeles, California. (Photo by Kevork Djansezian/Getty Images)
LEAVING: Hillary Clinton, Secretary Of State
US Secretary of State Hillary Clinton speaks to the press following talks with Japanese Foreign Minister Fumio Kishida at the State Department in Washington,DC on January 18, 2013. (NICHOLAS KAMM/AFP/Getty Images)
LEAVING: Ray LaHood, Secretary Of Transportation
WASHINGTON, DC - DECEMBER 05: Transportation Secretary Ray LaHood addresses the White House Tribal Nations Conference at the Department of Interior December 5, 2012 in Washington, DC. (Photo by Chip Somodevilla/Getty Images)
LEAVING: Timothy Geithner, Secretary Of The Treasury
U.S. Secretary of the Treasury Tim Geithner discusses the economy at Los Angeles World Affairs Council luncheon on July 31, 2012 in Los Angeles, California. (Photo by Kevork Djansezian/Getty Images)
STAYING: Eric Shinseki, Secretary Of Veterans Affairs
U.S. Army General Eric Shinseki speaks during day two of the Democratic National Convention at Time Warner Cable Arena on September 5, 2012 in Charlotte, North Carolina. (Photo by Alex Wong/Getty Images)