The House has passed a temporary government-wide funding bill that would prevent the government from shutting down at midnight Thursday.
The mostly party-line vote sends the bill to the Senate, which appears likely to change it and send it back.
Senate leaders are hoping to seal a long-sought agreement to add almost $300 billion over two years to the budgets for the Pentagon and domestic agencies, which otherwise face a budget freeze.
Neither Democrats nor Republicans on Capitol Hill want a repeat of last month's government shutdown.
But President Donald Trump unexpectedly raised the possibility Tuesday of closing things down again if he can't have his way on immigration, saying, "I'd love to see a shutdown if we can't get this stuff taken care of."