Having mounted an unprecedented push for a consumer protection agency as the centerpiece of a financial industry regulatory overhaul, consumer advocates may soon face a painful choice: bail or bite their tongues.

If Senate banking leaders drop plans for the Consumer Financial Protection Agency, its champions will have to decide whether to back a bill that's missing what they consider its essential ingredient, or abandon the financial services reform effort altogether.

Some Senate Democrats are already getting cold feet over the plan now being hashed out by Senate Banking, Housing and Urban Affairs Chairman Christopher Dodd, D-Conn., and panel Republican Bob Corker of Tennessee. Ongoing Senate negotiations are expected to produce a package as early as this week.

Financial industry players have enjoyed a particularly influential ally in the U.S. Chamber of Commerce.

A key question is whether the plan will include a standalone consumer protection agency or relegate those safeguards to an existing entity, such as the Treasury Department or even the Federal Reserve. Consumer advocates say the Fed, which has taken a beating over its failure to forestall the fiscal crisis to begin with, is the last agency they want to see in charge of protecting consumers.

"Our position is that it has to be an independent agency," said Robert Weissman, president of Public Citizen, which has helped lead the push for sweeping new financial regulations. He added: "It's hard to imagine a worse place than the Fed."

In theory, Weissman and his allies should have an easy sell. The House approved a comprehensive finance industry regulation bill in December that would set up an independent Consumer Financial Protection Agency, strengthen bank oversight, and clamp down on transactions involving credit cards, mortgages and derivatives.

Polls show that voters are fed up with banks and favor a crackdown. A full 68 percent of respondents to a February survey by the Pew Research Center had an "unfavorable" view of U.S. banks and financial institutions. Another 59 percent favored stricter regulation of financial corporations.

Consumer advocates also formed their first-ever coalition to fight for tougher banking rules, Americans for Financial Reform, which brought together some 200 civil rights, labor and consumer groups, and announced a projected $5 million budget last June. Individual labor and consumer groups also have rallied members to push for changes.

Some banks, moreover, have been forced to tighten their belts, even as they fend off increasingly anti-bank rhetoric from the White House. Lobbying expenditures at Citigroup Inc. dipped from more than $7 million in 2008 to about $5.6 million last year, according to the Center for Responsive Politics. At Bank of America, lobbying dipped to $3.7 million in 2009, from about $4.9 million the previous year, CRP data show. Goldman Sachs, too, trimmed its lobbying budget from almost $3.4 million in 2008 to $2.8 million last year.

But any banking industry pain turned out to be a "short-lived blip," according to Travis Plunkett, legislative director for the Consumer Federation of America. Overall, the commercial banking industry spent a collective $50.8 million on lobbying last year, a 6 percent increase over 2008, according to CRP. Moreover, the American Bankers Association spent almost $9.4 million on lobbying last year, while the National Association of Federal Credit Unions paid out close to $2.3 million.

Financial industry players have enjoyed a particularly influential ally in the U.S. Chamber of Commerce, which according to CRP spent $144.5 million on lobbying last year -- a full 60 percent increase over 2008. One of the chamber's leading initiatives has been its effort to kill the Consumer Financial Protection Agency, which it has spent millions attacking in a multipronged advertising campaign.

The chamber is also part of a new industry alliance that recently wrote to Senate negotiators, asking that regulatory reforms exclude non-financial companies. The Main Street Industry Alliance also includes the National Association of Manufacturers and the Industrial Energy Consumers of America, among others, according to Roll Call.

"They're back. And it's not fun," said Plunkett.

Despite being vastly outgunned, consumer groups have struggled to fight back with phone banks, demonstrations and even humorous gimmicks.

These include an online video released by Americans for Financial Reform that shows a string of former presidents waking President Obama in the White House late at night to urge him to push harder for a Consumer Financial Protection Agency. Created by the producers of Funny or Die, the video features a star-studded cast of former "Saturday Night Live" actors, including Dan Aykroyd as Jimmy Carter and Dana Carvey as George H.W. Bush.

Some analysts say the outlook remains strong for a meaningful financial services overhaul bill, and that it might still include a Consumer Financial Protection Agency. "The agency has become the lightning rod [or] flash point for the partisanship," conceded Anne Kim, economic program director for the progressive think tank Third Way. But she added: "It's not likely at this point that the agency will be the thing that destroys financial reform."

That's little consolation to consumer advocates now playing defense. As Plunkett put it: "In the last six months, it's been trench warfare. And the big banks are winning."