Lawmakers are facing a challenging situation as they return to Congress on Saturday. With less than 18 hours remaining, there is no clear solution to the ongoing dispute that could potentially lead to a wide-scale shutdown of the federal government. This impasse, primarily driven by internal disagreements among the Republican-controlled House of Representatives, is jeopardizing the functioning of various sectors, including national parks and financial regulation.

While the Democratic-controlled Senate plans to move forward with a temporary funding bill, a final vote may not occur for several days. If both chambers fail to pass a spending bill by 12:01 a.m. ET on Sunday, hundreds of thousands of federal employees will face funding shortages, hindering their ability to carry out their duties.

Government agencies have already prepared contingency plans that outline essential services, such as airport screenings and border patrols, as well as non-essential activities like scientific research and nutrition aid to disadvantaged mothers. Most of the government’s 4 million-plus employees, regardless of their work status, will not receive their salaries.

In response to the looming shutdown, celebrations for former President Jimmy Carter’s 99th birthday were rescheduled from Sunday to Saturday in Atlanta to avoid disruption.

This standoff follows closely on the heels of an earlier incident in which Congress narrowly averted a default on the $31.4 trillion national debt. Concerns about the potential impact on the US creditworthiness have emerged on Wall Street, with Moody’s ratings agency warning of potential consequences.

Typically, Congress passes temporary spending bills to provide more time for negotiating detailed legislation that determines funding for federal programs. However, this year a group of Republicans has blocked action in the House, pushing for stricter immigration policies and reduced spending compared to the levels agreed upon during the debt-ceiling crisis earlier this year.

On Friday, 21 Republicans joined forces with Democrats to reject legislation reflecting these demands, arguing that the focus should be on passing comprehensive spending bills for the entire fiscal year, even if it leads to a temporary shutdown. This decision has sparked frustration among other Republicans who believe it was a missed opportunity to advance conservative agendas.

House Speaker Kevin McCarthy mentioned the possibility of relying on Democratic support to pass a stopgap bill that would maintain current funding levels, but this move could face opposition from hardline members within his own party. However, McCarthy did not provide further details on this potential approach.

The Senate is scheduled to hold a procedural vote at 1:00 p.m. ET to extend government funding through November 17. While it enjoys broad bipartisan support, the Senate’s procedural hurdles could delay the final passage vote until Tuesday.

Even if the Senate bill passes, both chambers of Congress will need to reconcile their differences before sending any legislation to President Joe Biden’s desk. This process may encounter additional obstacles, as McCarthy has expressed opposition to the inclusion of $6 billion in Ukraine aid within the Senate bill.

McCarthy stated, “We continue to try to find a way out of this.”