Wall Street is making a last stand against regulatory reform in behind-the-scenes meetings in Congress, where lobbyists hope to use high-stakes horse trading to blunt provisions that could cost the industry billions of dollars.

While public attention is fixed on televised conference meetings aimed at finalizing legislation, financial lobbyists are working aggressively on the sidelines to weaken tough new restrictions proposed for debit card fees, risky bank trading, financial derivatives and bank capital requirements.

Major trade associations including the U.S. Chamber of Commerce and the Credit Union National Association are also mounting large-scale grass-roots campaigns to stir up opposition in the home districts of congressional negotiators and other key lawmakers who face reelection in November.

The conference is a good place for lobbyists to change legislation. Major negotiations don't take place in public. They're out of the spotlight where there's a better chance for one-on-one presentations, education and arm-twisting, said Ethan Siegel, an analyst with the Washington Exchange research group. What's done in the sunlight is more like reality TV.

The closed-door meetings come despite a vow last week by Representative Barney Frank, the Democratic chairman of the joint House-Senate panel that is crafting the final legislation, to conduct a very open process.

Wall Street securities firms, commercial banks, insurance companies, mortgage lenders and other financial firms have less than two weeks to reshape reforms intended to prevent a recurrence of the 2007-2009 financial meltdown that tripped the U.S. economy into its worst recession since the 1930s.

Lobbyists say the current fight is only the first leg of a running battle likely to see future rounds of regulatory legislation in Congress and years of legal wrangling.

MANY RESIGNED TO NEW REGULATORY REGIME

But as an estimated 3,000 lobbyists storm Capitol Hill in a final push on the current legislation, some say their clients have largely withdrawn from the fight to prepare for a new regulatory regime now widely seen as inevitable.

Most of the calls we're getting now are from folks who don't want us to lobby for them or change anything. Instead, they want advice on where things are going so they can be ready to comply, said a senior attorney at a lobby firm helping to lead the final push. Like many lobbyists involved, he requested anonymity.

The financial industry has spent over $286 million to lobby Congress since the reform debate began in earnest last summer, according to the nonpartisan Center for Responsive Politics. It also has donated more than $9 million to the campaigns of House-Senate conferees since the 2010 election cycle began last year.

But with anti-Wall Street sentiment rife among voters, and congressional elections less than five months away, the industry has seen numerous setbacks.

The movement is toward a stronger bill. That's the path we're headed down. People are fearful about being seen to water things down, said a trade association lobbyist.

Lobbyists say there may be scope to alter about 20 percent of the legislative language now before the 43-member conference panel, which will merge separate House and Senate bills into final legislation for President Barack Obama's signature.

Banks and credit unions still hope to eliminate an amendment that would reduce interchange fees charged to merchants for debit card use by inundating conferees, House and Senate leaders and other lawmakers with thousands of e-mails, letters, phone calls and office visits.

We're going to keep the pressure up, ramp it up with as many contacts as possible, said John Magill, a lobbyist for the Credit Union National Association.

Others are focused on more incremental changes in legislative language, hoping to ease restrictions for their clients.

Some lobbyists who believe there is no escape from a proposal by Democratic Senator Blanche Lincoln that would require banks to spin off their swap desks want the final bill to exempt in-house swaps even if it requires transactions done for clients to be handled through separately capitalized affiliates.

Industry interests also hope to cushion the impact of an amendment that would no longer allow banks to count trust preferred securities as Tier 1 capital -- the key measure of a bank's assets available to protect against potential losses. Lobbyists hope to get lawmakers to exempt current preferred holdings from the provision and agree to gradual implementation.

On interchange fees, banking and credit company lobbyists who view new restrictions as unavoidable want final language to contain looser fee constraints based on a broader range of card service costs.

The lobbying game on issues is pretty much done. Folks have voiced their opinions and now they're in the hands of God, one lobbyist said.

(Editing by Leslie Adler)