Legislators in the US Congress are racing to pass a spending measure before a midnight deadline that would trigger a partial shutdown of the US government.
A vote in the Republican-controlled House of Representatives is scheduled for Friday morning, but divisions within the party put the outcome in doubt.
If the House approves, the spending package moves to the Democrat-controlled Senate, where it is expected to have sufficient support to pass.
The $1.2tn (£951bn) legislation was the result of bipartisan negotiations and funds a broad swath of federal services through October, including a 3% increase in US defence funding.
The narrow Republican majority in the House of Representatives has struggled to pass spending legislation since taking control of the chamber last year.
A small but vocal group of conservatives called the Freedom Caucus has opposed proposed increases in government spending and called for new legislation to include changes to the US immigration law to address a surge of undocumented migrants at the US border.
"Everyone that I know and trust about the border, about overall spending, see it as a complete and total failure and capitulation by Republicans," Congressman Chip Roy of Texas, a member of the Freedom Caucus, said on Friday morning.
In recent government-funding fights, Democrats have joined with some Republicans to approve legislation that averts a shutdown.
That is the plan again, but there are indications that even with Democratic help there may not be enough Republican support in the House to meet the two-thirds majority necessary to approve the legislation under current rules.
If Congress fails to approve the legislation by midnight, operational funding would cease for some parts of the US government, although the full impact would not be felt until the new work week begins on Monday.
