Secretary of State John Kerry and Defense Secretary Chuck Hagel will testify at the Senate Foreign Relations Committee on Tuesday to argue the Obama administration's case for using military force in Syria.
A Senate source confirms that Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, will them at Tuesday's hearing. Kerry and Hagel will be testifying before a committee on which they both served as senators.
The hearing will begin the formal process for considering and debating President Barack Obama's request for congressional authorization to strike Syria in retaliation for a suspected chemical weapons attack that killed more than a thousand people in the suburbs of Damascus.
Senators are already rewriting the two page resolution that the White House sent to Congress on Saturday -- in part tom narrow its scope, according to Sen. Patrick Leahy, D-Vt., the most senior member of the upper chamber.
Tuesday's testimony is part of an all-hands push by the administration to convince a clearly skeptical Congress that punishing Syrian President Bashar Assad's government is the right thing to do.
On Monday, Republican Sens. John McCain and Lindsey Graham called on the president to make a stronger case to Congress and the American public. After meeting with Obama at the White House, McCain said that "a vote against that resolution by Congress, I think, would be catastrophic because it would undermine the credibility of the United States and of the president"
On Wednesday, the Foreign Relations Committee will hold a second, classified hearing on Syria. The Armed Services Committee will meet the same day, according to Sen. James Inhofe, the panel's ranking member.
Kerry will also testify at a House Foreign Affairs Committee hearing on Wednesday.
On Sunday, 83 lawmakers gathered at the Capitol for a classified briefing with White House national security and intelligence officials, some taking red eye flights from the West Coast to attend. It's the first of what's turning out to be many such briefings -- on Monday, leaders announced four more gatherings over the course of the next week for members to attend.
And on Monday, top officials -- including Kerry, Hagel, National Security Adviser Susan Rice, Director of National Intelligence James Clapper and Chairman of the Joint Chiefs Martin Dempsey -- were briefing House Democrats on an unclassified conference call.
The number of senior officials on that call helps illustrate how deep the skepticism is among even the president's usual allies on Capitol Hill. Many Democrats emerged from the Sunday briefing still skeptical about a possible strike.
"This is currently a partial blank check," said Rep. Chris Van Hollen, D-Md., a member of Democratic leadership. "It needs to be more narrowly drawn."