While President Obama continues to weigh whether the United States should intervene in Syria, British allies are pushing military intervention.

British Prime Minister David Cameron spoke in London on Thursday in response to the reported use of chemical weapons by the Assad regime against its citizens. Members of Parliament organized an emergency meeting to talk over the possibility of intervention. While the PM stated his support for an airstrike on Damascus, other leaders expressed trepidation on the matter.

Cameron stated that Parliament will vote twice in the next few days after consulting the U.N. on the necessity of military action, NBC News reported.

Conversations in the U.S. are happening just as slowly, and President Obama has stated that the White House "has not yet made a decision" on the next step.

His call on the Syrian issue might be slowed down even further, for 116 legislators have now signed a letter to the president calling his striking Syria without first getting the OK from Congress an unconstitutional act.

"Engaging our military in Syria when no direct threat to the United States exists and without prior congressional authorization would violate the separation of powers that is clearly delineated in the Constitution," the letter, headed up by Republican Representative Scott Rigell, read.

Indeed, it is true that Congress has the sole power to authorize war, or any form of military force. But even if the U.S. sent an unmanned drone into Syrian skies for a missile attack, it'd still constitute an act of war, and would require prior consent from Congressional leaders.

If the White House decided to storm Syria on grounds of humanitarian intervention, Congress would have to approve the move nonetheless, the New York Review of Books reported.

But as Commander-in-Chief, President Obama can go against this requirement. If he did, he wouldn't be the first - President Clinton, President Reagan and President Truman are all leaders in American history who have given green lights on military action before hearing the OK from Congress.

On Wednesday, House Speaker John Boehner wrote President Obama a letter concerning the conflict in Syria. In it, he questioned the direct military threat that Syria posed to the United States, and if an attack on Damascus would be legally justified.

"It is essential you address on what basis any use of force would be legally justified and how the justification comports with the exclusive authority of Congressional authorization under Article I of the Constitution," Boehner wrote.