WASHINGTON—The nation braced for a partial shutdown of the federal government, as time for Congress to pass a budget before a Monday midnight deadline grew perilously short and lawmakers gave no signs Sunday they were moving toward a resolution.

Leaders of both parties said they wanted to avoid the first federal closure since 1996, but their public appearances seemed aimed more at affixing blame for the impasse.

House Speaker John Boehner (R., Ohio) urged Senate leaders to pass legislation that the Republican-controlled House had approved early Sunday morning, which would fund the government through mid-December. But that prospect was remote, as the House legislation included a one-year delay of the new federal health law that Democrats have vowed to reject, as well as a repeal of the new law's tax on medical devices.

Democrats say Mr. Boehner himself could end the stalemate quickly by asking the House to pass the Senate plan for extending federal funding, which includes no provisions aimed at the health law.

Such a move would anger conservatives in Mr. Boehner's ranks and likely materialize only at the last minute, after keeping up the fight against the health law to the end. But it would bring relief to the many Republicans who fear that the public would hand their party the largest share of blame for a shutdown.