Senate Democratic leaders outlined an ambitious, yearlong jobs-creation agenda Thursday, but with just four days before they hope to hold their first floor vote on a package, they have yet to outline the elements of their first bill.

Senate Majority Leader Harry Reid (D-Nev.) said he hoped to introduce a bipartisan bill as soon as Thursday afternoon and hold the first votes on the measure Monday. He added that he wants to pass the bill before Senators leave at the end of next week for the weeklong Presidents Day recess.

Reid said that if he is unable to forge a bipartisan agreement, he would introduce a Democrat-crafted jobs package that he still hopes will garner GOP support on the floor.

The uncertainty surrounding the first bill of what Democrats envision as a series of job-creating measures throughout the year came from what aides described as delicate negotiations between Senate Finance Chairman Max Baucus (D-Mont.) and a few committee Republicans. Sources said the talks involve ranking member Chuck Grassley (R-Iowa) and Sen. Orrin Hatch (R-Utah).

Still, the first package is likely to include a one-year extension of the Highway Trust Fund, a small-business expensing tax credit, a continuation of the Build America Bonds program and a tax credit for businesses that hire new employees this year. The new hire tax credit is expected to be authored by Hatch and Sen. Charles Schumer (D-N.Y.), but Reid said he was leaving that decision to the Finance negotiators.

Republicans have also been pushing to extend other tax credits.

Reid indicated that the first bill would not likely be paid for by dipping into the $700 billion financial industry bailout money — a proposal that has created some controversy and opposition from Republicans. “The first package will be funded without any heartburn,” Reid said.

Senate Majority Whip Dick Durbin (D-Ill.) emphasized that Democrats were not wedded to every proposal in their “jobs agenda” and that they were “inviting our friends on the Republican side to join us” in crafting all the jobs-creation measures that the Senate would consider.

The jobs bills that Democrats will pursue, however, are likely to fall into discreet categories. Besides the tax incentives in the first bill, Democrats expect to consider measures focused on small-business lending and expansion, creating “green jobs” through energy-efficiency programs, funding transportation, water and school infrastructure projects, and providing money to states for teacher, police and firefighter hiring.

However, Democrats declined to provide any cost estimates for their proposals, cautioning that negotiations with Republicans would likely change the price tag — either higher or lower — of many of the bills.