Credit card swipe fee settlement far from a done deal AP file photo The lawsuit alleges MasterCard and Visa conspired with some of the largest banks in the country to set the swipe fee a merchant must pay every time a customer uses their credit card. By Herb Weisbaum, NBC News contributor The final approval of a proposed multi-billion dollar legal settlement over credit card "swipe fees" could be in jeopardy - or at least delayed - by more legal wrangling. Six of the 19 plaintiffs in the case, all big trade groups, now say they oppose the $7.25 billion deal reached in mid-July. The antitrust lawsuit, filed back in 2005, alleges MasterCard and Visa conspired with some of the largest banks in the country to set the swipe fee a merchant must pay every time a customer uses their credit card. Customers don't see that fee - which ranges from 1.5 to 3.5 percent of the purchase - even though we all pay for it in the form of higher prices. The banks and credit card companies say the fee is needed to pay for processing the transactions and to cover losses from fraud. Merchants hate the swipe fee, saying it reduces their profits and forces them to raise prices. The six retail organizations who brought this case say they're against the proposed agreement because it does not prevent Visa and MasterCard from boosting swipe fees whenever they want. "There is strong concern that the proposed settlement agreement will not achieve the litigation's most critical goal - to fundamentally change a broken marketplace in which swipe fees are set," said Dawn Sweeney, president of the National Restaurant Association in a statement issued last week. Without meaningful reform, there is concern that restaurateurs - many of who are small businesses - will continue to be negatively impacted by the unfair, non-transparent system that exists today. The other plaintiffs who object to the proposed settlement: the National Association of Convenience Stores, National Grocers Association, National Community Pharmacists, National Cooperative Grocers Association and National Association of Truck Stop Operators. Thirteen other plaintiffs, mostly small stores, have not objected. The July agreement, believed to be the largest antitrust settlement in U.S. history, must still be approved by a federal district court judge in New York. It requires the defendants, MasterCard, Visa and more than a dozen banks to: Pay about $6 billion to be distributed to the millions of merchants represented in the lawsuit. Roll back the credit card swipe fees for U.S. merchants for eight months. That would cost the credit card companies another $1.2 billion. Give American retailers the ability to recover that interchange fee by charging customers who pay with Visa and MasterCard a "checkout fee" - where allowed by law - equal to the interchange fee. Under the current Visa and MasterCard rules, retailers are not allowed to add such a surcharge. Visa called the settlement a "fair and reasonable deal." MasterCard noted that it represents "a solution reached after years of litigation and months of negotiation." Trish Wexler, spokeswoman for the Electronic Payments Coalition (a group that represents credit card companies and banks) called the settlement "the very best and most realistic outcome possible for all involved." In an email to NBC News.com, she wrote: "After a long and thoughtful process that produced a fair compromise, these trade associations who helped to design this settlement are now trying to go back for seconds. Instead of accepting the benefits of the settlement, these groups want even more, and will clearly never be satisfied. Where to we go from here? When the proposed settlement was announced three months ago, everyone considered it a done deal. But we're not there yet. And the entire deal could be torpedoed or at least delayed by more legal action. A lawyer representing most of the trade groups opposed to the settlements plans to file a motion challenging the agreement. And the National Retail Federation (NRF) recently authorized its lawyers to go to court to block the settlement. The NRF, which is not a party to this lawsuit, represents thousands of merchants who would be affected by it. Mallory Duncan, the NRF's senior vice president, told me the settlement is diametrically opposed to the goal of the lawsuit, "to reign in those high, anti-competitive, hidden fees" which he said have been rising at an alarming rate. "It's as if consumers said, "Give us some relief," and the card companies said, "OK, we'll shoot you, that will put you out of your misery,"" he said. If this settlement goes through, there is no limit to how high the swipe fees credit card companies and banks can impose. The world's largest stores, Target and Walmart have also gone on record as opposed to the proposed settlement. Walmart said the agreement would not "prohibit credit card networks from continually increasing hidden swipe fees, which already cost consumers tens of billions of dollars each year." It's assumed federal judge John Gleeson will hold more hearings before he decides whether to give preliminary approval to the settlement early next year. Despite the pushback, Visa and MasterCard believe the settlement will be approved. So does Morgan Stanley. Although in a report issued last week, the company's research department said it could take longer than expected for everything to be finalized. "If the settlement is not approved, the Morgan Stanley report noted, this case could go to trial, something many of those involved in this lawsuit - including judge Gleeson - do not want," they wrote. In the meantime, nothing changes. Retailers cannot impose a surcharge for using a Visa or MasterCard credit card - and it's not even certain very many would if they could. For example, Target and Walmart have both said such a fee is not in the customer's best interest. In fact, ten states prohibit merchants from imposing a credit card surcharge fee: California, Colorado, Connecticut, Florida, Kansas, Maine, Massachusetts, New York, Oklahoma and Texas. Morgan Stanley says these ten states represent 42 percent of retail sales in the U.S. There's one other way this could all shake out, retailers could offer discounts for cash transactions - if they want - at any time. That's something they can already do anywhere in the country. Herb Weisbaum is The ConsumerMan. Follow him on Facebook or visit The ConsumerMan website.