Rand Paul made a move to block the budget bill on Thursday night over objections to what it will do to the US deficit.
The US government has shut down for the second time this year after Congress failed to reach a deal on the budget.
Congress had hoped to pass a bipartisan two-year spending bill before a midnight deadline on government funding.
Friday’s partial shutdown came after Republican Senator Rand Paul delayed the vote over his objections to a massive budget measure, which would lift spending caps on US defence and domestic programmes by about $300-billion. It would also raise the government’s debt ceiling until March 2019.
Paul told the Senate that the bill, which would raise the deficit, is the “definition of hypocrisy” and that it would “loot the treasury”.
“I ran for office because I was very critical of [former] President [Barack] Obama’s trillion-dollar deficits,” Paul said.
Ryan did vote for a landmark tax overhaul bill in December that would add nearly $1.5-trillion to the national debt over 10 years.
The Senate is expected to still pass the spending measure after 1:00am local time (6:00 GMT). The bill would then be sent to the House for a vote.
If the measure is approved, and signed by President Donald Trump before the beginning of the workday, there would be no major interruption to government services.
It remains unclear if there are enough votes in the House to get the spending measure passed.
The White House had already begun to instruct government agencies to prepare for potential shutdown, local media reported.
No deal on DACA
This is the second time this year that the government has shut down. In January, members of Congress failed to reach a deal on immigration, which Democrats had initially said would need to be part of any spending agreement.
On Wednesday, House minority leader Nancy Pelosi, spoke for a record eight hours on the House floor, calling for a permanent measure that protects the nearly 800,000 undocumented people, known as “Dreamers”, who were brought to the US as children.
In September of last year, Trump announced he was ending the Deferred Action on Childhood Arrival (DACA) programme, giving Congress until March 5 to come up with a permanent solution.
The budget agreement “does not have my support, nor does it have the support of a large number of members of our caucus”, Pelosi said, as reported by the Associated Press earlier this week.
Senate Republicans have vowed to hold a debate on immigration earlier this month, but Dreamers and their supporters worry a solution will not be found before the March 5 deadline.—Al Jazeera