Tyson Foods Inc., the world's largest meat producer, says it will temporarily shut down nine of its beef and pork plants Monday because many of the workers plan to attend immigration rallies.

"While we understand the sentiment behind the May 1 events and support comprehensive immigration reform, we are not encouraging workers to participate in the rallies," Tyson spokesman Gary Mickelson said.

National immigrant organizations have been calling on people to skip work and avoid shopping Monday to demonstrate the economic power of immigrants. Rallies calling for less restrictive immigration laws are also being planned around the country that day.

Over the past two months, immigrant advocates have staged rallies and marches in several cities, some drawing tens of thousands of demonstrators, as Congress considers immigration reforms. Congress has been divided over whether to crack down on illegal immigrants or embrace them as vital contributors to the U.S. economy.