The 92 million Americans who are members of the nation's 7,600 credit unions have a train wreck in front of them - and the next two months are going to prove critical as they face an all-out lobbying steamroller to transfer billions of dollars from their pockets into the coffers of some of the largest corporations on Earth.

The Wal-Marts of the world have spent millions and years lobbying Congress to effectively eliminate a little known transaction fee known as "interchange" - or "swipe fees." Very simply, interchange is paid by merchants who want to use the vast debit card network.

This system processes billions of instant transactions safely and securely. It has increased sales, helped make online businesses viable and has made debit cards second only to cash as the preferred method of payment.

Such a highly advanced and consumer-friendly network costs money to operate. Until recently, the merchants who used the system paid for it, usually about 1 percent to 2 percent per transaction. These fees have spurred the creation of an enormous variety of free payment cards from credit unions, community banks and major institutions.

But the giant retailers' lobbyists were able to slip a provision into last year's Wall Street reform legislation that will create a government price cap on debit card interchange and cut it by about 70-90 percent below the current market rate.

What does that mean to the average person? Merchants are going to get a $15 billion windfall - with no requirement they pass their gain back to their customers.

That money is going to come from credit unions and others that issue debit cards. For the big banks that may mean that customers pay more, get fewer services and/or shareholders make less profit. And even with their enormous resources, in some cases they have already raised their fees to address the reduced revenue.

In a credit union, however, it's all about the consumer-member. As not-for-profit institutions, extra revenue gets channeled back to the credit unions' membership as higher savings yields, lower loan rates and lower fees. Last year, these savings to credit union members amounted to more than $6.5 billion.

So the merchants' larger paycheck will be signed by ordinary individuals and families. And, credit unions do not have the financial bases the major banks have to cushion the impact. In fact, most rely on the interchange revenue they realize just to offer debit card services.

For example, interchange revenue helps offset fraud costs. The data breach earlier this month at Michaels stores around the United States showed just how massive those costs can be. Credit unions and other financial institutions were not responsible for the breach, but they are the ones that will have to cover the cost of reissuing compromised cards.

To keep offering those debit services, banks will have little option but to charge fees, which will be borne most heavily by those who can least afford to pay them.

Congress has a chance to avert this train wreck before the regulation takes effect and transfers billions of dollars from debit card users to giant retailers.

In both the House and Senate, there are bills that would delay the price caps long enough to complete a review into their unintended consequences. Any regulation directly affecting so many Americans should have received proper study before it was passed. The least that can be done is for Congress to recognize the severity of situation and take another look before it's too late.

Bill Cheney is president and CEO of the Credit Union National Association. Readers may write to him at CUNA, 601 Pennsylvania Avenue NW, South Bldg., Washington, D.C. 20004; website: www.cuna.org.