Senate Majority Leader Mitch McConnell is expected to announce the timing of the upper chamber's vote around midday. But House sources say Speaker Nancy Pelosi and other Democratic leaders want to give their caucus ample time to review the still-unreleased bill text before deciding their next step. Because the House has "emergency convening power," the lower chamber could still vote before midnight, the senior aide noted.
That means Donald Trump would likely not get the final bill until Thursday or Friday to sign into law, which his top spokeswoman says he intends to do.
The Senate is expected to approve the bill on Wednesday with a large number of Republicans and Democrats voting in favor.
House leaders in both parties are still canvassing their members, meaning the exact coalition that pushes it across the finish line in the lower chamber is not yet known.
The massive bill, perhaps the largest stimulus measure in American history, includes direct payments for some Americans, small business loans, and help for large corporations with new guidelines to ensure those firms are not spending the monies improperly.
Even as the Senate prepares to approve it, Republican and Democratic leaders continue to attack one another about which side triggered a series of last-minute talks that left its fate in jeopardy.