Senate Democrats still are working on their version of new jobs-producing legislation, but the plan may end up being split into multiple, smaller measures, says Environment and Public Works Committee Chairman Barbara Boxer (D-Calif.).

The first bill in that series, she says, could include a 10-month extension of surface-transportation programs.  That would involve adding an estimated $20 billion to the Highway Trust Fund, whose financial health has been less than rock-solid.

If Senate Democrats do propose a multi-part plan, it would be a major change from the single-bill approach the House took.

In December, the House passed a $154-billion jobs package, including $47 billion for highways and other infrastructure programs. The House measure also adds $20 billion to the Highway Trust Fund and extends the highway and transit programs, but only through Sept. 30.

Appearing at a Capitol Hill press conference on Jan. 27, Boxer said that Democrats' plan has not been made final and "is subject to change." But she said she understands that the initial piece of legislation would be "a tight package."

Boxer said that first installment would include a surface-transportation extension through Dec. 31, with an infusion for the Highway Trust Fund. The federal highway and transit programs have been operating under extensions since last Sept. 30. The latest stopgap is set to expire Feb. 28.

The EPW committee has jurisdiction over federal highway authorization and policy matters.

Boxer also said that Finance Committee Chairman Max Baucus (D-Mont.) has come up with a way to pay for the envisioned 10-month transportation extension. Baucus would recapture interest earned on the Highway Trust Fund balance and add it to the trust fund itself.

Beyond that, according to Boxer, the initial piece of the Senate jobs legislation may include: 

--tax credits for small business, possibly for hiring new workers, or for other investments those companies make;

--a provision dealing with "Build America Bonds." Established under ARRA, these are federally subsidized bonds to help localities finance capital projects;

--extensions of COBRA health-insurance  coverage and unemployment benefits.

Boxer said that initial measure may be "the first of several packages" that Democrats propose, all aimed at producing more jobs.

She added that the first bill wouldn't require using money from the Troubled Asset Relief Program. The House-passed bill draws on $75 billion in TARP money to help fund the measure's infrastructure components. But some Republicans oppose using TARP funds for a new jobs bill.

Sen. Robert Casey (D-Pa.), who also spoke at the press conference, said he has proposed a "job-creation tax credit" for companies that add  jobs. "If you increase your payroll, you get a tax credit," Casey said. He added that under his proposal, small businesses' credit would be 20%.

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