A can of Campbell's Beef Vegetable Soup is constructed like a Chrysler: The beef most likely came from the company's plant in Argentina, the cans were made from Japanese steel, and although Campbell usually buys domestic produce, the vegetables could have been imported from anywhere in the world.

Consumers may not know that the meatballs in their Franco-American spaghetti were probably partly processed from New Zealand or Australian cattle, or that between December and April more than half of the fresh tomatoes consumed in the U.S. come from Mexico. Domestic manufacturers are not required to list where their ingredients come from, and retailers don't have to identify whether the bananas in the bin were grown in Guatemala or Honduras.

But there's a movement to change that. Over the past year, about half a dozen different "country-of-origin" labeling bills have been introduced in Congress. And recently, an amendment was added to the omnibus trade bill that would require country-of-origin identifications at the retail level for all domestically processed foods containing a significant percentage of imported ingredients, as well as all imported fresh foods.

The labeling issue adds grist to the current international trade debate, this time pitting some U.S. producers against domestic manufacturers and retailers -- and leaving consumers in the middle of another plea to buy America and save the American farmer.

While the United States still exports more food and raw agricultural products than it imports, over the past five years the numbers have narrowed. In 1981, according to the U.S. Department of Agriculture, food and agricultural exports exceeded imports by $26.6 billion; in 1986, exports exceeded imports by only $5 billion. Conversely, from 1982 to 1986, the dollar value on imported food increased by 41 percent. (In 1987, for the first time since 1981, food and agricultural exports are expected to rise slightly and imports to decrease slightly, according to the USDA.)

Campbell is "firmly committed to worldwide sourcing," said company spokesperson Jim Moran, because of the lower costs and assured supply of imported food. "Otherwise, we'd get clobbered by foreign competitors," he said. Moran said the company would support the position of the National Food Processors Association, which opposes mandatory country-of-origin labeling.

Dennis Phelan, director of legislative affairs at NFPA, said that such labeling would be "totally unworkable" for American processors who, for example, make a product such as beef stew that contains ingredients from any number of foreign countries. Since the company's sources may change depending on cost and availability of the ingredients, the number of potential label combinations would put the firm "out of business in about an hour," Phelan said. If a law made it difficult for companies to use imported ingredients, they'd stop doing it -- and switch to domestic goods, Phelan said.

Phelan believes that proponents of the measure don't care so much about consumers' right to know as they do about shutting out imports. Opponents see country-of-origin labeling as a protectionist move and a nontariff trade barrier.

Senator James Exon (D-Neb.), who offered the amendment to the trade bill in June, represents a state well known for its beef production. Country-of-origin labeling poses a "happy marriage between the consumer's right to know and protecting, to some degree, the markets of American producers of quality food," Exon said in a recent interview.

Exon said that the amendment would not ban the importation of foreign beef and that the labeling difficulty raised by food processors is a "totally phony argument." Food companies change their labels in some way or another every year for marketing purposes, Exon said. Besides, federal regulations would require "reasonable and practicable" application, meaning that the exact country of origin might not have to be identified, but rather a selection of possibilities, he added.

In a draft General Accounting Office report that addresses the issue of labeling of imported meat, the agency concluded that "insufficient evidence exists" that the benefits of country-of-origin labeling justify the costs of implementing, monitoring and enforcing such a requirement. Those costs would ultimately be passed on to the consumer, the report stated. GAO said that livestock producers have been pushing for country-of-origin labeling for the past 20 years.

During that period, domestic production of manufacturing grade beef declined and Australia and New Zealand emerged as the primary sources of the kind of meat used in ground beef, sausages, chili, stews, soups and frozen dinners. About 7 percent of the beef consumed in the U.S. is imported, although nearly 40 percent of the domestic ground beef supply contains imported beef, according to GAO. Many food processors, fast food companies and restaurants blend imported and domestic beef together in their products. (Imported manufacturing grade meat is generally leaner than the domestic variety.)

It's not just industry representatives who are concerned that mandatory country-of-origin labeling would impose a complicated monitoring system. The chocolate industry sees the measure as a threat to its trade secrets. According to Susan Smith, director of public and legislative affairs for the Chocolate Manufacturers Association of the U.S.A., the taste distinctions among Hershey, Mars and Godiva chocolates are largely due to the origin of the cocoa beans in each formulation.

Identifying country of origin for fresh produce is a health and safety issue as well as an economic one. Supporters of such labeling for fruits and vegetables believe that consumers have a right to know where their produce comes from since foreign countries may be using pesticides that are either illegal in this country or in excess of U.S. tolerances. Between 1979 and 1985, about 6 percent of the imported produce sampled and analyzed by the FDA contained illegal pesticide residues.

Nevertheless, "the solution is not to label {tainted produce}," said NFPA's Phelan. "That's absurd." The answer lies in strengthening enforcement programs so that the produce "doesn't come in to begin with," he said.

Rep. Leon Panetta (D-Calif.), who recently returned from a trip to Otay Mesa, one of California's primary points of entry for Mexican produce, said that he was surprised by the lack of communication between the Food and Drug Administration and Mexican officials concerning which pesticides are illegal in this country, the FDA's lax procedures in notifying the Mexican government when violations are found, and the lack of tough enforcement after violations are detected. In the meantime, in lieu of a more effective enforcement program, "we have the responsibility to educate the consumer as to the risks." Panetta said he has become "more sympathetic" to country-of-origin labeling because he believes it would do that.

U.S. farmers have to comply "with the strictest regulations in the world," according to Leona Lewis, president of Calfornia Women for Agriculture. Lewis' group, which has supported state efforts for country-of-origin labeling, said that labeling raw products is "something we desperately need. Everything else we buy -- clothing, liquor, you name it -- it's identified. If we don't market our own products to the best of our ability, who will?"

Since 1979, the state of Florida has had its own country-of-origin labeling act. According to testimony of Martha Rhodes, Florida's assistant commissioner of agriculture, such information has afforded consumers with "the basic information to make a conscious choice." Rhodes said that state costs to enforce these requirements have been "minimal" and that adding the words "From Chile" or "From Mexico" to produce placards has not been burdensome for retailers.

However, Clayton Hollis, spokesperson for Publix supermarkets, a Florida chain, said that the state's country-of-origin requirement is a "very difficult law to follow." Hollis said that particularly when it comes to separating and labeling the same produce item from different sources (e.g. oranges from Florida and Sicily) that it is "a big hassle."

Hollis said that where the produce comes from doesn't matter to Publix's shoppers. They purchase fruits and vegetables which are the "best looking and the best price, whether they be domestic or imported," he said.

While Sen. Exon believes that American consumers will be attracted to American meats because of their quality reputation, Sharon Bomer of the United Fresh Fruit and Vegetable Association, believes that "country of origin labeling is not going to make people buy American. Quite the opposite is true, Bomer said; consumer trends show an increasing demand for imports and exotics, at least when it comes to produce. In addition, a survey conducted by The Packer, the produce industry's trade publication, showed that out of 13 characteristics important to consumers when buying produce, country of origin ranked 12th, according to Bomer.

Consumers might use country-of-origin information in the same way they use brand names, said Mona Doyle, president of Consumers Network, a consulting firm that regularly polls consumers. When it comes to food, the cachet of imported products depends on the item, Doyle said. American meat has a very positive image, Doyle believes, while English, Canadian and French dairy products are seen as better than American. Perception of produce items is probably split, she added.

Consumers don't realize that they may be displacing American labor by buying foods such as Italian-made pasta, Doyle said. But consumers want imported ethnic foods, she conceded; it makes them think " 'I'm eating the authentic stuff.' "