House members demanding congressional approval for a military attack against Syria are making detailed legal arguments that ignoring Congress would violate the War Powers Resolution (WPR).

Dozens of House members are now on record as insisting that Congress must authorize military action against Syria, including more than 100 who plan to deliver a letter to the White House on Thursday.

That letter argues that the Obama administration is stretching its authority under the WPR, which was passed in 1973 and defines the circumstances under which the executive branch can commit military assets overseas.


Under the WPR, the president can "introduce United States Armed Forces into hostilities" pursuant to a declaration of war, specific statutory authorization, or under a national emergency "created by attack upon the United States, its territories, or its armed forces."

In the letter to be sent Thursday, members argue that Obama has already weakened that standard in regard to Libya. It notes that in 2011, the administration's Office of Legal Counsel said Obama can rely on his constitutional power to safeguard the "national interest" by conducting limited military operations in Libya.

The letter says that prior action went too far and sets a precedent for ignoring the WPR.

"We view the precedent this opinion sets, where 'national interest' is enough to engage in hostilities without congressional authorization, as unconstitutional," it reads.

The letter also disagrees with the administration's analysis that sending missiles into Libya did not amount to "hostilities."

"If the use of 221 Tomahawk cruise missiles, 704 Joint Direct Attack Munitions, and 42 Predator Hellfire missiles expended in Libya does not constitute 'hostilities,' what does?"

In a separate letter sent Wednesday, Reps. Walter Jones (R-N.C.) and John GaramendiJohn Raymond GaramendiThis week: Congress returns to chaotic Washington Trump labels Tlaib 'a despicable human being' Tlaib says Democrats have discussed detaining White House officials who don't testify MORE (D-Calif.) argue further that with no declaration of war and no congressional authorization, Obama must rely on a national emergency finding in order to strike Syria without congressional approval.

But they argued even that justification cannot be rationalized, as Syria poses no immediate threat to the United States.

"As none of these criteria have been met, we believe it is Congress's right and responsibility to be fully briefed on any potential plans to engage in military action in Syria, to assess whether such an intervention is in the national security interest of the United States and our allies, and to withhold or grant authorization for the use of military force based on this assessment," they wrote.

The administration has yet to offer any detailed hints about how it will proceed, although some congressional staff now believe a strike against Syria is imminent, and that it would likely be based on a national emergency rationale.

One possible rationale could be that Syria has chemical weapons that could fall into the hands of al Qaeda operatives and then be used to threaten or harm the United States. House Homeland Security Committee Chairman Michael McCaul (R-Texas) said this week that removing the threat that these chemical weapons might be used against American citizens is his top concern.

Chairmen of various House and Senate committees have spoken with senior Obama administration officials this week on Syria, a sign that the administration may be trying to fulfill its consultation requirement with Congress under the WPR before any strikes against the country.