WHITE SULPHUR SPRINGS, West Virginia (CNN) -- President Bush urged Congress Friday to quickly pass the economic stimulus plan that would give tax rebate checks to Americans, saying, "I strongly believe it would be a mistake to delay or derail this bill."
Bush said he understands "the desire to add provisions from both the right and the left," but added the package is "big enough to affect the economy in positive ways."
He spoke to a gathering of House Republicans, who praised his "perfect attendance record" at the annual Congress of Tomorrow retreat.
The stimulus package would use tax cuts to put spending money in Americans' pockets.
About two-thirds of the tax relief would be delivered in rebate checks to 117 million families beginning in May. Individual taxpayers would get up to $600 in rebates, working couples $1,200 and those with children an additional $300 per child under the agreement.
Businesses would get $50 billion in incentives to invest in new plants and equipment.
While the House reached a deal with the White House to advance the bill Thursday, many Senate Democrats want to include extended unemployment benefits -- a provision House Democrats dropped to reach the agreement with House Republicans and the Bush administration.
"The package is not complete. And while it is a very good first step, we need to move a little farther," said Sen. Chuck Schumer, D-New York.
Sen. Edward Kennedy, D-Massachusetts, issued a statement saying, "Working families should be assured that this agreement is not the final word. Families are in crisis, and it's not enough just to help with their taxes. I intend to offer amendments in the Senate to strengthen this package -- to provide unemployment insurance to workers looking for jobs, and to help families coping with high heating costs and skyrocketing food prices."
Some Democrats have said they may want to add Medicaid aid to states or a summer youth jobs program.
House Republican leader John Boehner of Ohio joined Bush's effort to push Senate Democrats to drop their objections. "It would be irresponsible for Senate Democrats to load this bill up with pork and other spending," Boehner said, without citing what he was referring to as "pork."
"Families and small businesses need help now, and this agreement shouldn't be derailed because of partisan politics," he said.
Democrats have said they do not consider their concerns about the bill to be partisan politics.
Treasury Secretary Henry Paulson met Thursday night with Senate Finance Committee Chairman Max Baucus, D-Montana, and Sen. Chuck Grassley of Iowa, ranking Republican on the committee, to begin negotiating the Senate bill.
Paulson met Friday with Senate Banking Committee Chairman Christopher Dodd, D-Connecticut, about housing and mortgage-related items in the bill.
After the meeting, Dodd said Paulson was not "enthusiastic" about the proposed changes.
Meanwhile, the House has not announced when it will hold the vote to pass its version of the package, despite the deal reached with the White House. E-mail to a friend
CNN's Ted Barrett and Brianna Keilar contributed to this report.