They successfully lobbied the U.S. Treasury Department to reopen the public-comment period on rules that direct banks to accept the matricula consular as one of two forms of ID a person may use to open a bank account. Already, more than 80 financial institutions accept it.

These groups opposed to illegal immigration also enlisted some Republican members of Congress who in July pushed a bill through the U.S. House of Representatives to regulate issuance of the ID card.

The moves have not been well-received by Mexican politicians. They say, and other U.S. Republicans agree, that the matricula can contribute to homeland security by accounting for immigrants even if they are in the country illegally.

The Treasury Department had received about 30,000 responses by the time the comment period closed at the end of July, officials said recently. The majority favored keeping existing rules, meaning the matricula consular would remain a valid form of ID. The Treasury Department's final decision on what foreign documents banks will be allowed to accept to verify a customer's identity is expected later this summer.

The House measure would regulate documents such as the matricula by requiring foreign consulates to share the identities of matricula recipients with the U.S. State Department and to maintain databases so the cards cannot be duplicated. It also would require recipients to notify consulates of address changes.

The measure, part of a spending bill, passed the House 226-198. A similar bill has yet to be considered in the Senate.

Top officials at the Homeland Security Department also are working with other agencies to develop a policy for accepting foreign ID cards, including the matricula consular.

Pro and con

The matricula for years had a relatively low profile: It was one of many services Mexican consulates provided their citizens. But when the Mexican government decided to upgrade security features of the card last year, in part as a response to the terrorist attacks of Sept. 11, 2001, the card gained a new political visibility.

The new matriculas, issued through 47 Mexican consulates in the United States, bear the cardholder's photograph, U.S. address and information visible only under infrared light. Applicants must present a birth certificate to obtain it.

Groups seeking stricter immigration limits say that by making it easier for undocumented immigrants to open bank accounts, gain access to certain public buildings and borrow library books, the matriculas legitimize the immigrants' illegal stay in the United States.

"What is happening is that, partly with the help of its allies in the U.S., the Mexican government is clearly pushing a well-orchestrated campaign to get American institutions to accept this card," said Steve Camarota, director of research at the Washington, D.C.-based Center for Immigration Studies, a think tank that wants tougher immigration enforcement. "If you're a legal resident of the U.S. with a valid visa, you have a number of documents that are much more readily accepted. The card is explicitly and entirely for the use of people in the country illegally."

The FBI also has expressed serious reservations about the card. One top FBI official in June told lawmakers that the matricula "is not a reliable form of identification and prone to fraud."

Still, more than 1,000 U.S. law enforcement agencies, including Phoenix police, and 409 city governments across the country, including Phoenix, have endorsed it as a valid form of ID. They are joined by 125 county and 32 state governments.

More than 1.19 million matriculas were issued across the United States in 2002, according to the Mexican Foreign Ministry. Through mid-August, more than 571,000 matriculas had been issued this year.

Pro-immigrant groups say the matricula confers no special immigration status, so undocumented workers cannot use it to enter the United States, cannot use it in place of a driver's license and cannot use it to get a job.

But it does give them access to banks. So, instead of using an expensive money-wiring service, immigrants open an account and mail an ATM card to their families, who withdraw the money directly and pay a small fee.

Mexican immigrant workers' remittances to their families are a major source of income for Mexico. Last year, workers who came to the United States for plentiful low-skill jobs that are scarce back home sent $10 billion home in remittances. In the first three months of this year, the amount was $2.7 billion.

"The matricula card has become an important tool for opening financial institutions to the unbanked," U.S. Rep. Luis V. Gutierrez, D-Ill., told a House subcommittee in June. "It is a win-win situation. The financial institutions can tap new customers. And the customers can gain access to fundamental financial services that were previously unattainable."

U.S. Sen. John Cornyn, R-Texas, who has introduced a plan to allow immigrants to become temporary guest workers, also favors the matricula.

"I believe it is better to identify individuals in the United States than to not identify them," Cornyn said at a Mexico City news conference. "It's important to recognize what that card is and what it is not. As a means of identification, I think it's positive, but it is not anything more than that in my view, or should not be recognized as anything more than that, such as conferring legal status or special privileges on the holder of that card."

"It (the matricula) serves me for identification," said Juan Manuel Luna, who has been in Phoenix about a year and came from Guadalajara, Jalisco, to sell Herbalife products. "I hadn't had something like this before."

He said the matricula makes everyday transactions easier and safer.

"It's more a way of obtaining identification that can help in any situation," added Ruben Ramirez, who heads a hometown club in Phoenix for immigrants from Chihuahua.

Anger in Mexico

Mexican politicians have been unanimous in their derision of U.S. congressional and Treasury actions.

Some blamed the moves on U.S. resentment for Mexico's opposition to the war in Iraq. Others, like Patricia Aguilar Garcia, a Mexican Congress member in charge of a migration issues caucus, blamed the U.S. thirst for access to Mexico's oil industry. She referred to an earlier House resolution that suggested the United States might negotiate with Mexico on immigration if there is a quid pro quo on oil.

"A lot of us Mexicans believe Americans are desensitized," Aguilar Garcia said. "They don't realize that Mexicans don't leave because they want to. They leave because of necessity."

Gustavo Mohar, migration consultant to Mexican President Vicente Fox, said legislating the rights of foreign governments is a "very uncommon practice" that seems to fly in the face of international law. U.S. State Department officials have asked, informally, about access to matricula databases, Mohar said. Mexico would have to consider questions of privacy, confidentiality and mutual legal assistance in weighing such a request.