The firing of workers trying to unionize at the Smithfield meat packing plant in Tar Heel, N.C., has prompted Sen. Edward Kennedy (D-Mass.) to take aim at the Department of Homeland Security. The senator has urged the department to suspend its regulations that allow the government to check the Social Security numbers of workers the numbers it has on its master lists.

Kennedy, who chairs the Senate’s Department of Health, Education, Labor and Pensions Committee, delivered a letter this week to Department of Homeland Security Secretary Michael Chernoff asking that the department’s controversial IMAGE program, as it is called, be held “in abeyance” until it can be reviewed by Congress.

Pointing to Smithfield’s cooperation with Homeland Security’s IMAGE program, Kennedy wrote that the company used the program to fire workers without giving them adequate time to respond to questions about mismatched information.

The government raided the Smithfield plant several weeks ago, arresting 21 workers on immigration charges.

The United Food and Commercial Workers Union has worked for 14 years to organize the plant, which slaughters 30,000 hogs a day.

The Homeland Security IMAGE program is being avoided by most companies but has been used to fire and arrest workers at Smithfield. Smithfield volunteered itself for the program once the national campaign to support workers trying to unionize got underway.

Several leaders of the organizing effort at Smithfield have received letters threatening them with job termination. The union has called for an end to arrests because Smithfield is using the arrests to threaten and intimidate workers who support the union.

The union points out that this is in violation even of the Department of Homeland Security’s own guidelines on worksite enforcement during labor disputes.

Gene Bruskin, director of the Smithfield Justice Campaign, called Kennedy’s move “an important step in stopping Smithfield from using its cooperation with IMAGE as a smokescreen to intimidate workers.”

“The company has been found in legal rulings to have illegally threatened workers who are advocating for better conditions with arrest by immigration authorities,” Bruskin said. “Now they are making good on those threats and using our immigration laws to intimidate workers.”

Kennedy called upon the secretary of Homeland Security not to issue any regulations regarding social security mismatches until Congress is able to complete action on comprehensive immigration reform.

In an “open letter” to the union, just before the move by Kennedy, Smithfield President Joe Luter asked for a union election, offering to help pay for a “neutral” outside observer to assure a fair vote.

The union dismissed the “offer,” saying the recent firings of immigrant workers have created an atmosphere of fear the company is using to its advantage.

“The company is using this as a public relations move,” said Mauricio Castro of the North Carolina Latino Coalition. “All of a sudden they’re talking about the opportunity to vote or hold elections. When you intimidate people or especially after these raids, what kind of a free election do you have?”