At a Nissan Plant in Mississippi, a Battle to Shape the U.A.W."s Future Altimas on an assembly line at the Canton, Miss., plant await installation of power steering pumps. Nissan is the state's second-largest private employer. CANTON, Miss. - The United Automobile Workers - desperate to make inroads in the anti-union South where Toyota, Volkswagen and other foreign automakers have assembly plants - has never tried a unionization drive quite like the one at the Nissan plant here. Rogelio V. Solis/Associated Press Morris Mock, a paint technician at Nissan's Canton, Miss., plant, signed a petition in May calling for the automaker to allow union recruitment without company opposition. It has enlisted thousands of union members in Brazil to picket Nissan dealerships there as the company prepares to co-sponsor the 2016 Olympics in Rio de Janeiro. The union has sent a team of Mississippi ministers and workers to South Africa, where Nissan has an assembly plant, to try to embarrass the company with accusations that it violates workers" rights at the Canton plant. Over the next few weeks, a delegation of U.A.W. leaders and supporters will travel to Tokyo, and to Paris, where Renault, Nissan's partner, is based, to publicize a report by a Cornell University professor that asserts that Nissan's managers have illegally threatened to close the Mississippi plant if workers vote to unionize. These efforts are largely directed at Nissan's part-Brazilian, part-French chief executive, Carlos Ghosn, a renowned cost cutter who has said the company prefers communicating with its Mississippi workers without a union. Closer to home, the actor Danny Glover has embraced the U.A.W."s cause, speaking at colleges across the South to recruit students to distribute union fliers at Nissan dealerships. The union has also helped create a group of students and community and religious leaders, the Mississippi Alliance for Fairness at Nissan, which includes the N.A.A.C.P. The alliance often uses the slogan, "Labor Rights Are Civil Rights." At a time when the U.A.W. has fewer than one-third of the 1.5 million workers it had in 1979, its organizing push in the South has taken on urgency and is being watched closely by labor leaders across the country. "It's a life-and-death matter for the U.A.W. to succeed in the South," said Nelson Lichtenstein, a professor and labor historian at the University of California, Santa Barbara. That's why they've put their best organizers into this campaign. The unionization battle has badly divided workers at the gleaming white Nissan plant here, which stretches four-fifths of a mile along Interstate 55 and produces 450,000 Altimas, Sentras and other vehicles a year. The pro-union forces say many workers are backing the U.A.W., while anti-union workers insist the union has little chance of gaining majority backing. Some anti-union workers wear T-shirts saying, "If you want a union, move to Detroit." Despite the union's previous failures in the South, Bob King, the U.A.W."s president, has undertaken its most ambitious campaign in the region. In addition to Canton, it is also pushing to organize Volkswagen's plant in Chattanooga, Tenn., and the Mercedes-Benz plant in Vance, Ala. "Bob King has basically staked his legacy on organizing these international assembly plants," said Kristin Dziczek, director of the labor and industry group at the Center for Automotive Research. Unless they unionize more of the automotive work force in the country, they will become wage takers, not wage setters. If the U.A.W. fails to win at the foreign companies" plants in the South, Ms. Dziczek said, they will pull down wages at General Motors, Ford and Chrysler. The union faces rough going in Mississippi, she said, considering the embarrassing loss it suffered in 2001 when workers at Nissan's plant in Smyrna, Tenn., voted two to one against joining the U.A.W. Mr. King vows better results this time. "What's different this time is there is really strong and active community support," he said. Noting that unions in Japan, Germany, Australia and Britain are backing the Mississippi fight, he added: "That kind of global pressure on them, as a labor rights violator, will make a big difference. There are outrageous violations of the workers" right to organize." Union officials say they have not filed any complaints with the National Labor Relations Board but might do so. Ricardo Patah, president of Brazil's gigantic General Workers Union - it has seven million members and has pledged to picket dozens of Nissan dealerships - said in an interview, "We're not going to stop until they have a union inside the plant in Mississippi."