That deal is being threatened by Snowe's fight with Reid, an aide told The Hill.

Reid said Democratic leadership had its side of the agreement but suggested Republicans were abusing the process. 

“I don't know how much more good faith we could show than what we have already shown,” he said. “There has been no way of ending this so we are going to file cloture tonight."

Although the SBA funding bill is noncontroversial, senators from both parties have taken advantage of the open amendment process to file more than 125 amendments — of which only about 20 are germane.

The underlying Small Business Reauthorization Act, or S. 493, would provide funding for the Small Business Innovation Research program and the Small Business Technology Transfer program, which Democrats say would create jobs.

The Senate adjourned about 6:45 p.m. on Monday and is set to return at 10 a.m. Tuesday, at which time it will continue consideration of the small-business bill. 

-- Erik Wasson contributed to this report.