In a floor speech Tuesday morning, Reid said it is going to be “extremely difficult for us ... to get to complete this bill in a timely fashion.” He also said the prospects for securing the necessary 60 votes to win passage of the $194 billion measure are murky.

Reid said the outlook is muddy because, in addition to being tasked with navigating a complex series of votes, two senators have indicated they need to leave Washington by Thursday. There is also the matter of Sen. Edward Kennedy's (D-Mass.) illness, which is expected to keep him off Capitol Hill this week, and the uncertain schedules of the Democrats’ two presidential candidates, Sens. Barack Obama (Ill.) and Hillary Rodham Clinton (N.Y.).

“To make a long story really short, we have a really complicated path to go to complete our work,” he said.

Democrats have set June 15 as a deadline for getting the bill done, and the Pentagon has warned that it may start to lay off employees if more war funding is not approved by that time.

Senate Minority Leader Mitch McConnell (R-Ky.) called the process Democrats have employed to get the bill done “offensive” and criticized the majority for slow-walking the emergency bill and adding provisions that would prompt a presidential veto.

McConnell said he was concerned that Reid would employ a parliamentary tactic known as “filling the tree” to limit amendments that could be offered to the bill. Reid has yet to lay out his floor strategy to move the bill quickly.

The must-pass bill contains $165 billion for military operations in Iraq and Afghanistan, and more than $25 billion in domestic programs, such as a 13-week extension of unemployment benefits and an expansion of educational benefits for military personnel under the GI bill. It also calls for troops to be redeployed from Iraq by June 2009.