A Senate panel on Wednesday reluctantly accepted White House strictures on spending for a massive highway bill (search), but senators from both parties vowed to find more money for the popular construction and jobs measure when it reaches the Senate floor next month.

The $284 billion bill to fund highway and public transit programs over a six-year period "is still not sufficient for the investment we need for our roads and bridges," said Sen. Kit Bond, R-Mo., a senior member of the Environment and Public Works Committee (search).

Missouri's bridges are some of the worst in the nation and "we kill three more than three people a day on Missouri's roads," the senator said.

The panel approved, on a 17-1 vote, the highway portion of the bill: the Senate Banking Committee is to consider the transit section on Thursday, with the legislation moving to the full Senate after the Easter recess.

The House last week passed its version of the $284 billion package, and lawmakers from both chambers are eager to get a bill to the president this spring so states can sign contracts for the summer construction season.

Republican Sen. George Voinovich said his state of Ohio would lose 4,000 jobs if Congress fails to act quickly.

The previous six-year bill, funded at $218 billion, expired in September, 2003, and Congress has had to pass six temporary extensions to keep money flowing to the states at the old level because of disputes with the White House. Last year the administration said House and Senate proposals, which ranged up to $375 billion, were too high and threatened a presidential veto of any bill that added to the federal deficit.

This year the White House says it will accept $284 billion but revived the veto threat for anything above that figure.

But Sen. Max Baucus, D-Mont., said that was "way too low." Baucus, top Democrat on the Finance Committee, promised that "we will find additional funding" before the bill reaches the Senate floor.

Much of the drive for a more generous bill stems from the dissatisfaction of states that pay more into the highway trust fund than they get back in federal grants. Currently states are guaranteed 90.5 cents back for every dollar they contribute in federal gas taxes, and there is pressure to increase that minimum guarantee to 95 percent.

Sen. James Inhofe, R-Okla., chairman of the Environment and Public Works Committee, said that at $284 billion the guarantee could only be raised to 92 percent. He noted that senators would try to raise the money level on the Senate floor and "that wouldn't be a bad idea."

That sentiment was echoed by Sen. Jim Jeffords, I-Vt., who heads the minority on the panel. "The funding proposals from the White House for our nation's transportation needs have been inadequate and received in the Senate like advice from a back seat driver."

The committee also approved a renewable fuels bill sponsored by Sen. John Thune, R-S.D., that passed the Senate last year but died when it was incorporated in a stalled comprehensive energy bill.

The bill would require refineries to blend 6 billion gallons of ethanol (search) into gasoline by 2012, up from 5 billion in last year's bill, and increases the use of biofuels produced from agriculture products.