The warning, delivered in a letter to the White House, adds to the uncertainty surrounding the agency, created by the Dodd-Frank Act last year over the objections of Republican lawmakers and financial-industry lobbyists.

Forty-four Republican senators, led by Richard Shelby of Alabama, the top Republican on the Banking Committee, signed the May 2 letter made public yesterday. They wrote that they want the agency’s director to be replaced by a board of directors, its funding brought under congressional control and its operations subject to more oversight from other bank regulators.

“No person should have the unfettered authority presently granted to the director of the Consumer Financial Protection Bureau,” the senators said in the letter signed by Republicans including Minority Leader Mitch McConnell of Kentucky. “We believe that the Senate should not consider any nominee to be CFPB director until the CFPB is properly reformed.”

Democrats control 53 of the 100 votes in the Senate, so the 44 Republican signatures ensure they wouldn’t be able to garner the 60 needed to overcome objections to a nominee.

Payday Lenders

The consumer bureau was conceived as a response to what proponents said was the failure of existing regulators to protect consumers from risky financial products that contributed to the credit crisis. Under Dodd-Frank, the bureau has authority to regulate products financial firms from the biggest banks to mortgage originators and payday lenders.

Banking lobbyists fought the idea from its inception, arguing that an agency separate from prudential regulators would threaten the safety and soundness of the banks. Financial firms have expressed concern that the bureau’s rules will limit the products they can offer or result in new regulatory compliance costs. Recently, for example, agency officials said they would consider restrictions on credit-card debt-protection products, from which big card issuers earned $2.4 billion in 2009.

The structural changes proposed by the senators in their letter echo proposals advancing in the Republican-controlled House. Banks including Bank of America Corp., Citigroup Inc. and Capital One Financial Corp. have lobbied on the legislation, according to public filings. Two financial industry trade groups, the American Bankers Association and the Consumer Bankers Association, have done the same, the filings show.

Elizabeth Warren

“Republicans fought the creation of a strong consumer watchdog from the start and now they are at it again,” Senate Banking Committee Chairman Tim Johnson, a South Dakota Democrat, said in a statement yesterday.

Obama hasn’t nominated a director for the consumer agency. Last year he named Harvard University law professor Elizabeth Warren as an adviser to set up the bureau after then-Senate Banking Committee Chairman Christopher Dodd, a Connecticut Democrat, said she couldn’t get the 60 votes needed to be confirmed as director.

Treasury Secretary Timothy F. Geithner set July 21 as the date the agency would start operations as an independent agency. The Republican move leaves Obama with the choice of missing that deadline, acceding to the demands or going around the lawmakers by making a temporary appointment during a congressional recess.

Other Republicans

Two Republican senators — Scott Brown of Massachusetts and Lisa Murkowski of Alaska — didn’t sign the letter to Obama.

Warren, who has been criticized by banks and Republicans for her role in a 50-state investigation of the mortgage industry by state attorneys general, hasn’t been ruled out by the White House as a candidate for the permanent post.

The consumer agency has been a polarizing entity since the idea was first included in the Obama administration’s financial overhaul proposal in June 2009. The U.S. Chamber of Commerce pledged millions of dollars to “kill” the bureau, running campaign advertisements and working a grassroots campaign that resulted in more than 200,000 letters designed to sway lawmakers thought to be on the fence.

Initially drafted as a standalone agency, Dodd reached a compromise to place the bureau inside the Federal Reserve in an effort to appease Republican critics. In the end, only three Republicans voted for the final measure.

Jamie Dimon

Since the passage of Dodd-Frank, banks and the business lobby have focused on changing the bureau’s structure. Jamie Dimon, chairman and chief executive officer of JPMorgan Chase & Co. addressed its creation in a letter to shareholders last month that noted his concerns about a standalone agency.

“It has been widely reported that we were against the creation of a Consumer Financial Protection Bureau (C.F.P.B.),” Dimon wrote in the April 4 letter. “We were not — we were against the creation of a standalone C.F.P.B., operating separately and apart from whatever regulatory agency already had oversight authority over banks.”

The Obama administration, which touted the bureau as one of the cornerstones of the regulatory overhaul, remains committed its independence, according to Amy Brundage, a White House spokeswoman.

“For far too long, American consumers have fallen victim to fraud, misleading claims, and powerful special interests and the President believes that American families who were the hardest hit by this financial crisis deserve an independent watchdog to protect consumers and prevent predatory lending and other abuses in the future,” Brundage said in an e-mailed statement.

Frank Keating, the head of the American Bankers Association, endorsed the move by Senate Republicans.

‘Critical Check’

“We appreciate and support the 44 senators who are calling for structural changes to the CFPB before considering any nominee,” Keating said in an e-mailed statement. “These commonsense reforms strike the right balance and provide a critical check on the bureau’s broad authority.”

Travis Plunkett, director of legislative affairs for the Consumer Federation of America, said giving in to the Republican demands would “give big banks extraordinary power over the bureau’s operations” even before it begins work.

“The measures that the senators are demanding were all considered and rejected by Congress last year,” Plunkett said in an interview.