The hastily called meeting drew 20 food vendors to a gray trailer on the small campus of Casa de Maryland Inc., an immigrants' rights organization in Silver Spring.

"We have to show them that we have a political force," community organizer Juan Carlos Ruiz told the group of Salvadoran immigrants turned business owners. "People have started small since the time they came here. Then they had the opportunity to become a professional. We want that for our community as well."

The men and women listening to Ruiz make their living illegally selling stuffed tortillas, known as pupusas in El Salvador, from white trucks in Langley Park. Offering food from trucks and cars is against the law in Prince George's County.

For more than five years, the pupusa vendors have been trying to get the ban on their businesses lifted. As many as 150 such vendors operate in Prince George's. Often they are allowed to sell food without worry, but, periodically, county inspectors and police crack down and confiscate a vendor's food or issue a hefty fine. Vendors said fines are sometimes hundreds of dollars and wipe out a week's earnings.

"We have suffered under the threat that they are going to throw us out," said Juan Rivas, who started operating his truck -- Latin Food -- off New Hampshire Avenue seven years ago. "They give us a ticket and say move out of here and they treat you like a delinquent."

The effort to overturn the ban on mobile vending is a show of the growing political savvy of Prince George's County's burgeoning Latino immigrant community, which has become more organized over time. The pupusa vendors gather monthly, have started a petition drive and have met with other mobile vendors in Prince George's, including people who illegally sell crabs and barbecue. They have also begun lobbying County Council member William A. Campos (D-Hyattsville), whose district includes Langley Park, to get the law changed.

"This is a very controversial issue, and we need to take everyone into consideration," said Campos, who was elected six months ago and hopes to craft a compromise between the pupuseros and people who oppose mobile vending.

The vendors have won the tentative support of other County Council members in the past. Last year about this time, Peter A. Shapiro, who was County Council chairman, proposed to allow pupusa vendors to operate in a certain part of Prince George's, similar to a Montgomery County law that allows a limited number of vendors to sell their goods in specific places.

The ban on most mobile food vending -- ice cream trucks were never outlawed -- was passed a decade ago. The idea was to clean up the county's image; to county officials that meant getting rid of the crab trucks and big barbecue pits that served food on Landover Road, Route 50 and other major thoroughfares. That was before the county's Latino population grew to more than 7 percent. In Langley Park, where most of the pupusa vendors operate, 60 percent of the population is Hispanic. The pupuseros often obtain food-preparation permits from the county Health Department but cannot get a business license. The businesses have proliferated by bringing a taste of El Salvador to immigrants in Prince George's for about $5.

Some in the community oppose the change to the law because of the crowds, traffic and noise that the pupuseros attract, and the trash that some trucks leave behind. It is a clash that LaVerne Williams, president of the Lewisdale Civic Association and chairman of an alliance of six additional civic groups that oppose mobile vending, said she does not think can be overcome. For seven years she has lived in Lewisdale, one of many, small, historic neighborhoods that surround the immigrant enclave of Langley Park.

"With [the vendors] all around, it makes it look very bad for the community," she said. "It makes it look like a third world slum. They cannot operate in residential areas."

Campos said he thinks he can solve the problem by finding a commercial area that will allow the pupuseros to operate, keeping them out of residential areas. He plans to have a proposal by year-end.

Ruiz and the pupuseros hope their organization and persistence will push the councilman to move faster.

"We aren't begging for anything," he told the vendors at the recent planning meeting. "We are asking to be contributors to this county. I need you to all bring five people with you next time, and get your petition sheets completed. On the other side is a lot of pressure, and we have to put more."

"We have suffered under the threat that they are going to throw us out," says Juan Rivas, a vendor.Food vendors met last month under the auspices of Casa de Maryland to plan how to make their occupation legal.

Elvia Diaz serves a customer in Langley Park.