U.S. Senator Lindsey Graham (R-SC) and Senator Chuck Schumer (D-NY) (R) speak during a push for new bipartisan media shield legislation during a news conference at the U.S. Capitol in Washington, July 17, 2013. Also pictured is co-sponsor Senator Amy Klobuchar (D-MN) (L). REUTERS/Jonathan Ernst (UNITED STATES - Tags: POLITICS MEDIA)
Sen. Lindsey Graham (R-S.C.) )REUTERS/Jonathan Ernst)

Sen. Lindsey Graham (R-S.C.) pressed the Obama administration Sunday to allow Congress to hear from American survivors of the September 2012 attack on the U.S. diplomatic mission in Benghazi, Libya, and renewed his promise to block confirmation of all of President Obama’s nominees if it does not.

“A year later, Congress doesn’t know anything about it from those who lived through it,” Graham said of the attack during an appearance on Fox News Sunday.

Graham’s vow to block nominees threatens to delay the confirmation of Jeh Johnson as homeland security secretary and Janet L. Yellen as head of the Federal Reserve.

“I shouldn’t have to make these kinds of threats,” he said. “I’m hoping they will relent.”

Graham said he wants to hear “from the mouths of people who were on the ground” about the events leading up to the attack.

An explosive report on CBS’s “60 Minutes” last week has reignited attention to the attack. But the account provided by the British supervisor of local security guards protecting the U.S. diplomatic mission has been called into question.

“If he’s lying, I want to know that,” Graham said.