Senate Majority Leader Harry M. Reid (D-Nev.) formally introduced the resolution Friday  allowing limited military strikes against Syria, setting in motion a key test vote that will likely take place Wednesday.

Reid, in a brief session, set the resolution on the Senate agenda and plans to then officially set a mid-week vote to clear an expected filibuster attempt from conservative opponents to the military strikes.

Reid will need 60 votes in that first key vote. Democrats are expecting some liberal opponents of the strike to vote to defeat a filibuster, and then oppose the plan on final passage, when a simple majority will be needed.

Reid said the resolution would allow a "limited" strike.

"Many, many people have been killed with this, including almost 500 children," Reid said of the Syrian regime's alleged use of sarin gas.

With Senate Democrats divided on the resolution — Joe Manchin (D-W.Va.) announced his opposition Thursday, following no votes from several Democrats in the Foreign Relations Committee earlier this week  — the final vote could be close or even require Vice President Biden to cast a tie-breaking vote.

If opponents use up all the procedural tactics at their disposal, the earliest a final vote could occur would be Sunday. More likely, it will come by Friday.

The bigger question mark remains the House, where opposition is much deeper at the moment. Speaker John A. Boehner (R-Ohio) has not outlined a formal timeline for the House's consideration of the resolution.