Nugent sent his letter just a day after senior administration officials held a teleconference on Syria with more than two dozen congressional leaders. Sen. James InhofeJames (Jim) Mountain InhofeSenate panel unanimously approves water infrastructure bill Defense bill moves forward with lawmakers thinking about McCain Overnight Energy: EPA moves to roll back chemical plant safety rule | NASA chief says humans contribute to climate change | Pruitt gets outside lawyer MORE (R-Okla.) said Secretary of State John KerryJohn Forbes KerryJohn Kerry to NYU Abu Dhabi: We can't address world problems by 'going it alone' Juan Williams: Trump's dangerous lies on Iran Pompeo: US tried, failed to achieve side deal with European allies MORE spent most of the call trying to convince members to support military action, but without laying out any specific military options.

Nugent's letter mirrored the argument that dozens of other members have made: The civil war in Syria does not constitute a direct threat to the U.S. that can be used to justify military intervention. Nugent called arguments that Syria is a threat "unsubstantiated."

"If your administration believes that our allies are under imminent threat from Syrian chemical weapons, I would like to see the intelligence underlying that belief," he wrote. "The American people would as well. And if there is no intelligence to support that claim, then your administration cannot possibly use an imagined imminent threat as a legal justification for unauthorized military action."

On Thursday, the British Parliament voted down a motion to use force against Syria, and many members of the House have argued that a vote to use military force would also fail in Congress. Members are also increasing their calls for President Obama to address the nation on why an attack is warranted and to allow Congress to debate the question before acting.