The bill failed to gain the two-thirds needed — 261-155 — with 30 Republicans voting in support while 16 Democrats opposed the legislation.
The House willl try again with a simple majority vote on Wednesday, as the $33 billion six-month extension will now head to the House Rules Committee.
Rules is expected to approve a rule for consideration tonight, which would set up the legislation for floor consideration Wednesday. That vote won't require two-thirds support for passage.
Even if the House passes the measure, however, there's doubt the Senate has the votes to approve it before leaving for the July 4 break.
Democratic Sen. Ben Nelson (Neb.) said Tuesday that if the bill's costs aren't offset with other spending cuts or tax increases, it won't get his vote.
With the Senate missing Sen. Robert Byrd (D-W.Va.), who passed away early Monday morning, three Republicans would have to back the measure.
So far, Sen. Olympia Snowe (Maine) is the only Republican who has voiced support for passing an extension without paying for it.
Republicans and Nelson have argued the bill adds too much to the nation's debt.
The House bill under consideration extends unemployment benefits through November but will not include the extra $25 included in checks as part of last year's stimulus bill.