Hundreds of Christian leaders are on Capitol Hill Tuesday asking their senators to vote against confirming former Sen. Chuck Hagel as the next secretary of defense.

The leaders, being hosted by Christians United For Israel, the largest pro-Israel organization in the United States, are concerned about Hagel's foreign policy record on Iran and Israel.

The group held an emergency summit Monday night with Senate Minority Whip John Cornyn, R-Texas.

"On July 2001, 96 U.S. senators voted to extend sanctions against Iran. Chuck Hagel was one of only two senators who voted against sanctions," the Texas lawmaker noted in a recent CNN op-ed.

"One of the biggest foreign-policy challenges of Obama's second term is preventing Iran from acquiring nuclear weapons -- which means we need a defense secretary who understands the nature and magnitude of the Iranian threat," he continued.

"Based on his record, Hagel does not," Cornyn concluded.

On Tuesday, 400 Christian leaders will make their case against the former Republican lawmaker in individual meetings with their respective senators.