Mounting pressure from Jewish groups and members of Congress has led the largest kosher slaughterhouse in the United States to start searching for a new CEO less than two weeks after federal agents arrested nearly 400 of its employees in a massive immigration raid.

Aaron Rubashkin — the founder of Agriprocessors in Postville, Iowa — announced last week that he intends to find a replacement for his son Sholom as company CEO.

The announcement follows statements from three Jewish organizations raising the specter of a boycott, the launch of a campaign by the United Food and Commercial Workers Union and a call from Rep. Bruce Braley (D-Iowa) for an investigation of the company.

“The best course of action for the company, its employees, the local community and our customers is to bring new leadership to Agriprocessors,” the senior Rubashkin said in a statement.

The Brooklyn butcher and Chabad-Lubavitcher, who founded the company in 1987, added, “The company has begun the search for a new permanent chief executive officer. We have engaged a team of industry experts to help us identify and secure a new leader who can help us meet the needs of Agriprocessors today and in the future. We will make more information on the search process available by the end of next week.”

The statement reiterated that “due to pending legal issues” the company would not respond to details about the raid. They include allegations of underage employment, sexual harassment and overtime violations.

Rubashkin’s move to replace his son comes as Agriprocessors is facing mounting legal problems and boycott. The company’s problems have raised fears about a possible shortage of kosher meat and fired up the debate over whether Jewish religious bodies should take a more active role in monitoring the working conditions at kosher factories.

In response to the raid and related allegations about the situation at the plant, the Jewish Labor Committee issued a statement May 23 calling for a boycott of Agriprocessors.

The company sells its kosher meat under various labels, including Aaron’s Best, Aaron’s Choice, Rubashkin’s, European Glatt, Supreme Kosher, David’s and Shor Habor.

In its statement, the Jewish Labor Committee asserted that the company had displayed “a clear pattern of employer negligence and even lawlessness,” including the violation of child labor laws and toleration of various forms of worker abuse.

The committee’s statement was followed by a “request” from the Conservative movement’s top bodies that kosher consumers “evaluate whether it is appropriate to buy and eat meat products” from Agriprocessors.

That same day, Uri L’tzedek, a project started by students at Yeshivat Chovevei Torah, a liberal Orthodox rabbinical school in Manhattan, began circulating a petition asking Agriprocessors to pay its workers at least the federal minimum wage, abide by laws pertaining to workers’ rights and treat employees according to Torah standards.

“Until these changes are made, we feel compelled to refrain from purchasing or consuming meat produced by your company, and will pressure every establishment with which we do business to cease purchase of your meat,” the petition reads. “Effective June 15, 2008 we will stop patronizing any restaurant that sells your meat.”

Meanwhile, the food workers union has taken out advertisements in major Jewish newspapers detailing the allegations against Agriprocessors. The union, which has waged a legal battle over its still unsuccessful efforts to organize plant workers, also has launched a Web site, EyeOnAgriprocessors.org, to publicize claims against the company.

The May 12 federal raid is said to be the largest of its kind in U.S. history. Of the 389 illegal immigrants apprehended, 297 pleaded guilty within days and were sentenced to short prison terms or probation, to be followed by deportation to their native countries.

Speculation is rife over whether prosecutors are investigating the company itself, especially after one Postville resident with ties to Agriprocessors confirmed last week that he had been summoned to appear before a grand jury.

A spokesman for the local U.S. Attorney’s Office would not comment on the matter.

In Washington, the House Committee on Education and Labor held a hearing May 20 on the raid, focusing mainly on its impact on the children of detained workers. But members of Congress also have expressed concern that the raids targeted illegal workers while letting their employers off the hook.

Braley, who represents the northeast Iowa area where the plant is located, has called for an investigation of the company.

“Until we enforce our immigration laws equally against both employers and employees who break the law, we will continue to have a problem with illegal immigration,” Braley said.