Updated: 8:45 p.m.

The Senate continued to lurch toward a close Monday as lawmakers held out hope of bolting from Washington before Christmas Eve so they could spend at least the holiday weekend at home.

Although Majority Leader Harry Reid (D-Nev.) had wanted to finish on Monday evening a continuing resolution funding the government through March, Republicans were still reviewing the bill.

The Senate was scheduled to hold a procedural vote on the CR on Tuesday morning. Because the bill is relatively straightforward — it only includes a handful of small earmarks, including a geothermal provision sought by Reid — GOP and Democratic leadership aides predicted the funding measure would advance and could be completed by Tuesday night. However, Republicans would first have to yield back the 30 hours of debate time allowed after the procedural vote in order to hold a final vote by evening.

The bill’s passage would remove one of the three main hurdles standing between the Senate and adjournment and clear the way for an endgame strategy on the new Strategic Arms Reduction Treaty with Russia, which the chamber is scheduled to take up following completion of the CR. The Senate easily defeated three GOP amendments Monday evening that would have changed the treaty and effectively kill the deal.

Democrats and Republicans were also discussing the possibility of allowing amendments to the resolution of ratification, a nonbinding document that would allow Republicans to register their objections without endangering the treaty itself. That, in turn, could sway a number of fence-sitting Republicans to support the treaty. Ratification requires a supermajority of two-thirds of all Senators present and voting — 67 votes in the full chamber.

According to aides in both parties, the treaty could go in one of two directions. If Tuesday’s planned procedural vote, which needs 60 votes, receives a strong showing of GOP support and comes close to the number needed for ratification, Republicans could cut short the period of debate time after the procedural vote. That could mean a final ratification vote as early as Wednesday, most aides predicted.

Republicans, however, showed no signs of giving in Monday: They spent much of the day attacking the deal and forced a rare three-and-a-half-hour closed meeting of the Senate to debate classified issues related to the treaty. If they decide to run out the full 30 hours of debate on the bill, a final vote could be delayed until Thursday.

Such a delay would push back votes on a health care bill for Sept. 11 first responders, the final piece of major legislative action that Reid has scheduled for the lame-duck session.

While that measure has enough GOP support to easily pass in the Senate, and public pressure to do so has been growing steadily over the last week, Republicans could still filibuster the bill and delay passage for several days.

Leadership aides said they remained hopeful to avoid such a scenario and to have a final vote conducted before Friday. But if a filibuster is thrown up and Republicans demand the full 30 hours of debate time after a procedural vote to break the blockade, passage could be delayed until next week.

The uncertainty in the Senate is spilling over into the House’s schedule.

House Members had hoped to vote on a continuing resolution Tuesday and then to jet home for Christmas, but a more significant floor schedule now appears likely, given that the Senate has unexpectedly started moving a series of bills that will need House passage. The chamber could remain in session for much of this week and potentially next week.

A food safety overhaul and the America Competes Act, which would reauthorize spending on science, education and technology programs and agencies, could potentially keep House Members in town another day. The first responders health care bill that is making its way through the Senate could prompt them to stick around longer or even return after Christmas.

Steven T. Dennis contributed to this report.