The U.S. Senate on Wednesday was poised to pass legislation funding the federal government from Oct. 1 to Dec. 9 and avert a shutdown of agencies this weekend.
Senate Majority Leader Mitch McConnell announced the vote on the stop-gap spending bill would begin at 2 p.m. EDT (1800 GMT).
First senators will cast a procedural vote to speed up debate on the legislation. If senators, as expected, are supportive, the Senate could promptly vote on passage, sending the measure to the House of Representatives.
The breakthrough came after Republicans pledged to support passage by year's end of separate legislation helping the city of Flint, Michigan recover from a long-running water crisis that has exposed children and other residents to lead contamination.
Earlier, Republican House Speaker Paul Ryan and Democratic leader Nancy Pelosi reached the deal late on Tuesday, hours after a piece of legislation known as a continuing resolution (CR) aimed at avoiding the shutdown failed to garner enough votes to advance in the Senate.
A conservative group, Heritage Action, on Wednesday said the spending bill "falls far short of conservative expectations" and urged Congress to defeat it. But with House and Senate members eager to go home to campaign for re-election, the measure appeared headed toward passage.
Without the temporary spending bill, which is set for passage shortly before Congress recesses until after the Nov. 8 elections, many federal agencies will run out of money when the federal fiscal year ends at midnight EDT on Friday (0400 GMT Saturday).
Democrats in the Senate and House had vowed to oppose the CR until Republicans agreed to an aid package for Flint, a city of more than 100,000 people that has had lead-tainted drinking water for more than two years.
Under the deal reached between Ryan and Pelosi, the House will vote on Wednesday on an amendment to a separate water resources bill that would provide a $170 million aid package for Flint. A Senate version of the bill contains $220 million for Flint and other cities with problem water systems.
Democrats have also complained about Republican unwillingness to eliminate CR language that prevents the Securities and Exchange Commission from requiring companies to report their political activity.
Once passed by the House, the two chambers would hammer out compromise legislation after the Nov. 8 elections. The Flint money would be contained in that measure.
(Reporting by Richard Cowan and David Morgan; Writing by Doina Chiacu; Editing by Nick Zieminski, Alan Crosby and Bernard Orr)