An emergency spending bill to speed military assistance to Ukraine and Israel faces its next critical hurdle in a rare Sunday vote, as Republican senators continue to jockey for a chance to make politically divisive revisions to the legislation.
The $95 billion measure, which would also fund humanitarian assistance for civilians in conflict zones and address threats to the Indo-Pacific region, easily cleared a series of test votes last week with bipartisan support, even though G.O.P. senators had voted to kill a previous version of the bill that included measures to address border security.
Some of the Republican senators who have helped nudge the foreign aid bill along have warned that their support for its final passage — a vote leaders hope to hold on Tuesday — depends on having the ability to propose changes on the floor, including several related to the border. While they have acknowledged that it is unlikely such proposals could secure the 60 votes needed to amend the bill, the exercise of voting on them still allows them to show the G.O.P. base — and former President Donald J. Trump, whose criticism doomed the earlier version — that they tried to force the changes through.
But by Sunday morning, party lawmakers had yet to complete a list of potential revisions that Democratic leaders would accept.
“We still hope our Republican colleagues can work with us to reach an agreement on a reasonable list of amendments,” Senator Chuck Schumer, Democrat of New York and the majority leader, said on the floor, adding: “We will keep working on this bill until the job is done.”
Even if leaders can strike a deal, the Senate could be in session for the long haul on Sunday. Though the planned procedural vote was scheduled to take place around 1 p.m., aides were making plans over the weekend to ensure that senators would be able to watch the Super Bowl, carting extra televisions into the Capitol and ordering pizza, in case they were called to vote on a sudden deluge of amendments.
The Republican wish list of revisions to the foreign aid bill primarily focuses on the southwestern border. It includes a measure mirroring a restrictive border enforcement bill that the House passed last spring with Republican votes alone.
Republicans have also been demanding a vote on a measure to strip $7.9 billion in economic assistance for Ukraine from the bill, arguing that the United States should focus on military assistance alone and let European nations help maintain the country’s infrastructure through the war.
The G.O.P. is split between senators who want to hold votes on such measures on principle, but are prepared to support the legislation even if it does not pass, and Republicans who have committed to vote no unless such partisan changes are made.
“We did spend four months promising the American people that we would secure our own border before we focused on other countries’ borders,” Senator Tom Cotton, an Arkansas Republican who is firmly opposed to the bill, said on “Fox News Sunday.” He added that he also had “serious concerns about the $19 billion of nondefense aid in there.”
Democrats have responded with their own demands for revisions, such as a proposal from Senator Richard J. Durbin of Illinois, the Senate’s No. 2 Democrat, to give lawful permanent residence to certain undocumented immigrants brought to the United States as children.
Such proposals are unlikely to earn enough support to be included in the final bill.
Not every proposed revision concerns migration. A subset of Democrats has also been angling for votes to limit the impact of Israel’s military campaign in Gaza, including a measure to prohibit Palestinian civilians from being forcibly displaced.
