From mighty meatpacking plants to tiny taco stands, U.S. businesses are making plans to deal with Monday's nationwide pro-immigration boycott, which could keep millions of people away from their jobs.

Contingency plans range from juggling schedules to hiring temporary workers to closing down altogether, companies say.

Organizers say millions of immigrants and their supporters will participate in the demonstrations, scheduled to protest legislation that would declare illegal immigrants felons and erect a fence along much of the U.S.-Mexico border. Such job actions could close down several major cities, they say.

We're going to close to show support, said Robbie Mendez, who works at his family's Las Palmas Taco Bar in Santa Cruz, California, which has eight employees. Immigrants do a lot to help run this country and, I believe, to help the economy.

Dozens of companies have sought advice from the Atlanta-based law firm of Jackson Lewis, which specializes in labor issues, said one of its partners, Jonathan Spitz.

It shows the extent that people are taking this seriously, said Spitz, who said some companies were even considering opening on Sunday in order to close on Monday.

There's been an awful lot of cooperation by companies and by employees, Spitz said. No one who has called is looking to fire employees when there are better solutions.

Participation in the pro-immigration events can range from marching in mass rallies to wearing white on the job.

In the heavily ethnic New York City borough of Queens, hundreds of workers plan to join hands and create a human chain along a major thoroughfare. Many businesses are expected to close for the day or for a few symbolic minutes.

'DAY OF SOLIDARITY'

We are calling it a day of solidarity with the immigrants, said Eduardo Giraldo, chairman of the New York Statewide Coalition of Hispanic Chambers of Commerce.

We are asking for compassion from the employers toward the employees, said Giraldo, who plans to close his insurance company. If people decide not to go to work, please don't fire them because they take time off to participate.

The construction industry may feel one of the biggest impacts from the proposed walkout, said Challenger, Gray & Christmas Inc., global outplacement consultants.

Some 18 percent of the 11.2 million U.S. construction workers are foreign-born, and construction is the largest employer of undocumented immigrants, with an estimated 1.4 million unauthorized workers, Challenger said.

In Arizona, which shares a border with Mexico and has a large immigrant population, construction companies may not know until the last minute who will show up on Monday, according to David Jones, president of the Arizona Contractors Association. He said he expects employers to tolerate absences.

I think employers realize that without a functional guest worker program that we have serious problems, he said.

Estimates show Arizona will face a shortage of some 40,000 skilled laborers in construction by 2014, he said.

The appetite for construction in the Southwest is so ravenous that getting employees to come and work for you is a major obstacle. If you're going to be competitive, you had better have a good working relationship, he said.

In the Midwest, the meat production unit of Cargill Inc. decided to close down operations at five beef plants and two hog plants, freeing thousands of employees to participate in immigration rallies.

We talked with employees and many wanted to participate in the May 1 activities. Because we share the concerns of many employees ... we felt it was appropriate to change the schedules, said Mark Klein, spokesman for Cargill, the nation's No. 2 beef producer and No. 3 pork producer.

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