The Senate failed to vote Thursday on a government funding deal amid stalled negotiations, leaving the federal government on the brink of a partial shutdown with just over 24 hours remaining before funding expires.

Earlier in the day, Senate Democrats said they had reached an agreement with the White House to advance a plan that would separate funding for the Department of Homeland Security from a broader package of five other appropriations bills. Under the proposal, the five-bill package would fund federal programs through the end of September, while DHS would receive a short-term extension of two weeks to allow further negotiations over disputed provisions.

To move forward quickly, the Senate would need unanimous consent to take up the plan before Friday night’s deadline. As of Thursday evening, however, objections from senators in both parties appeared to be blocking progress.

“Tomorrow’s another day, and hopefully people will be in a spirit to try and get this done tomorrow,” Senate Majority Leader John Thune said as he left the Capitol late Thursday.

If objections cannot be resolved by Friday, the government would enter a partial shutdown. The Senate is scheduled to reconvene at 11 a.m. Friday to attempt to reach an agreement. Any deal would still require approval by the House, making at least a brief shutdown increasingly likely.

Sen. Lindsey Graham, R-S.C., emerged as the most outspoken opponent of the proposal. He confronted Senate leadership earlier Thursday, calling the agreement negotiated by Democrats and the White House a “bad deal” and vowing to block its advancement.

Graham said his objections stem from what he described as the “unconscionable” treatment of Immigration and Customs Enforcement officers under the current proposal.