WASHINGTON — President Obama's call to rein in the use of earmarks was met with derision yesterday even from some of his past reformer allies, dealing an early blow to his attempt to change how business is done in Washington.

Obama signed what he called an "imperfect" $410 billion measure to fund most government agencies through September. He criticized the more than 8,500 projects costing more than $7.7 billion that lawmakers inserted into the bill and declared that "this piece of legislation must mark an end to the old way of doing business and the beginning of a new era of responsibility and accountability that the American people have every right to expect and demand."

But as he vowed to press Congress to shun earmarks, a bipartisan collection of lawmakers said the proposals he offered yesterday would do little to curb the practice and would do nothing to address the appearance of a connection between campaign contributions and spending programs ordered up by lawmakers.

While Obama campaigned on a promise to bring reform to Washington, the reality remains that most lawmakers believe it is their constitutional prerogative to direct money to their districts. Earmark supporters and opponents alike said Obama's words would carry little weight unless he also vowed to veto critical legislation that is full of spending projects.

"Absent a genuine veto threat, he's just spittin' in the wind," said Rep. Jeff Flake, R-Ariz., an earmark opponent who walked through the House chamber yesterday carrying almost 100 pages of approved spending requests from a lobbying firm that is under federal investigation.

Representing less than 2 percent of the discretionary federal budget, earmarks have become a lightning rod for critics who say they waste taxpayer money on projects that are requested more to win votes for lawmakers at home than they are for their merits. The connection between earmark recipients and the lobbyists who made campaign donations to lawmakers to secure their passage was central to criminal investigations that landed former lobbyist Jack Abramoff and former congressman Randall "Duke" Cunningham, R-Calif., in federal prison.

"The problem is not earmarks, the problem is secrecy which led to abuses in the past," said Sen. Daniel K. Inouye, D-Hawai'i, chairman of the Senate Appropriations Committee.

Obama and congressional Democratic leaders offered a proposal that would require lawmakers to publish on their Web sites all requests they make to the appropriations committees. (Currently, lawmakers are required to detail only requests for funding that is granted.) The earmark lists would be publicly available when subcommittees consider the spending requests under their jurisdiction, weeks earlier than they are now. Agencies would be given 20 days to deem certain proposals inappropriate.

Obama said he would direct agencies to conduct competitive bidding for earmarks targeted to private companies and also threatened to highlight earmarks considered inappropriate by asking Congress to revoke funding for such projects in the future.