President Trump signed an executive order Tuesday evening compelling meat processors to remain open to head off shortages in the nation’s food supply chains, despite mounting reports of plant worker deaths due to covid-19.

Trump invoked the Defense Production Act to classify meat plants as essential infrastructure that must remain open. Under the order, the government will provide additional protective gear for employees as well as guidance, according to a person familiar with the action who spoke about the order before it was signed by the president. The person was not authorized to disclose details of the order.

Trump’s plan to sign the order was first reported by Bloomberg News.

Trump alluded to the plan Tuesday morning during an Oval Office meeting with Florida Gov. Ron DeSantis (R). “We’re going to sign an executive order today, I believe,” Trump said. “It was a very unique circumstance because of liability.” He did not elaborate.

Worker safety experts say such an order would prevent local health officials from ordering meat companies to use their the most effective weapon available to protect their employees from the coronavirus — closures. They also fear that it would also undercut newly issued federal health guidelines designed to put space between plant workers. Trump has not publicly explained which provisions within the act he will rely on to compel plants to remain open or grant companies protection from workplace safety requirements.

At least 20 meatpacking plants have closed in recent weeks because of covid-19 outbreaks, according to an analysis by The Washington Post. The United Food and Commercial Workers, which represents thousands of workers at U.S. meat plants, said Tuesday that at least 17 have died of covid-19, the disease caused by the coronavirus, and at least 5,000 have been directly affected by the virus.

“America’s meatpacking workers and our nation’s food supply are in greater danger every day that companies and leaders fail to act during this outbreak,” UFCW President Marc Perrone said in a news release. “It is clear that our food supply chain is threatened, and that is why our country’s elected and corporate leaders must act now.”

Industry analysts say pork and beef processing has fallen 25 percent because of these outbreaks. Major meat companies, including Tyson Foods, Smithfield Foods and JBS USA, have repeatedly touted their essential role in the nation’s food supply chain, often resisting calls from government officials and labor advocates to close their facilities due to outbreaks.

“The food supply chain is breaking,” John H. Tyson, chairman of Tyson’s board, wrote in a full-page newspaper ad published Sunday in The Post, the New York Times and the Arkansas Democrat-Gazette.

“We have a responsibility to feed our country,” the ad said. “It is as essential as health care. This is a challenge that should not be ignored. Our plants must remain operational so that we can supply food to our families in America.”

In a statement released Tuesday evening, Tyson spokesman Gary Mickelson said that the company appreciated the White House’s “efforts to help the food supply chain.”

“The safety of our team members will remain our top priority as we work with the [Agriculture Department] on next steps,” he said. “We’ve been screening worker temperatures, requiring protective face coverings and conducting additional cleaning and sanitizing. We’ve also implemented social distancing measures, such as workstation dividers and more breakroom space.”

Smithfield in a news release said it supported Trump’s decision to activate the DPA and said it would protect workers’ livelihoods and American consumers from “protein shortages.”

“The company is grateful to its employees and its union representatives, who are frontline responders, for their patriotism and willingness to step up in a selfless way to keep food on tables during this global pandemic,” the release added in part. “Importantly, the company believes that the executive order will provide priority assistance in securing an ongoing supply of critical PPE, as well as aid the company in securing broader COVID-19 testing for its employees.”

Representatives from JBS did not immediately respond to requests for comment.

Many workers say the Occupational Safety and Health Administration and companies have not done enough to protect them from fast-spreading outbreaks that have hobbled production and devastated rural communities in which they are based. Some workers say companies put production over their safety and have failed to provide adequate protective gear and promote social distancing.

On Tuesday, the Centers for Disease Control and Prevention and OSHA released interim guidance for meatpacking and processing facilities. It outlined procedures for cleaning shared equipment and reconfiguring workstations. It also included information on how companies can use physical barriers to put at least six feet between employees, who typically stand shoulder to shoulder in the plants.

It also called for the use of personal protective equipment and revising attendance policies to ensure employees are not penalized for taking sick leave because of the coronavirus. But like previous CDC and OSHA guidance for workplaces during the pandemic, it is voluntary and not enforceable.

“These outbreaks that have sickened thousands and killed dozens were not inevitable in the meat industry,” said Debbie Berkowitz, a former senior OSHA official who is an expert on meat processing plants. “If OSHA had started enforcement, employers like the meatpacking industry who don’t prioritize safety voluntarily would have implemented the CDC guidance and prevented these outbreaks of death and disease in meatpacking.”

Jason Walsh, executive director of the BlueGreen Alliance, a coalition of labor and environmental groups, said: “Workers in the American food industry are vital to us all, but the terrible working conditions that already existed in that industry have only been exacerbated by the covid-19 virus. Donald Trump is finally using the Defense Production Act, but not to ensure that American manufacturers produce the protective equipment that essential workers so desperately need to be safe. Instead, Trump is using the DPA to try to force workers back on the job in unsafe conditions. It doesn’t get more wrong than that.”

Berkowitz said Trump’s decision will undercut local health officials’ power to make meat plants comply with newly issued federal guidance that would have limited workers’ coronavirus exposure.

“The president has just undermined all efforts to stop the spread of the disease in plants,” Berkowitz said. “He is essentially saying they must be allowed to operate and that there should be no specific requirements plants must follow to stop the spread of this disease.”

Trump’s order would render meaningless the guidance the CDC issued Sunday, including keeping individual workspaces six feet apart and ensuring plant employees are not facing one another.

“Without putting in specific safety requirements — beyond masks — the disease will continue to spread through the plants and into the community,” Berkowitz said.

But the courts and the Justice Department have ruled that the DPA “doesn’t give the president or anyone else the authority to grant broad immunity from other federal requirements, or from state laws,” said Adam R. Pulver, an attorney with Public Citizen who litigates claims about the scope of government authority.

Legal experts say there are serious questions about whether legislation Trump cited authorizes the president to grant broad immunity to businesses from workplace, environmental and other safety protections, nor is it clear whether Trump can order a shuttered manufacturing plant to reopen.

“The immunity applies when companies are sued for things they had to do in order to comply with the Defense Production Act,” Pulver said, “but not for choices they made in refusing to comply with other legal obligations.”

For example, he said, prior court rulings on the law indicate that plants would probably not be granted immunity if they refused to comply with local health officials’ orders to provide protective gear or did not take steps to allow for social distancing.

Rep. Robert C. “Bobby” Scott (D-Va.) called Trump’s expected order “profoundly disturbing” in a statement and called on the White House to harness the DPA for the manufacture of personal protective equipment.

“If President Trump orders people to work in meat processing plants but refuses to protect their health and safety,” Scott said, “the result will be more preventable illnesses, the tragic deaths of workers across the country, and ultimately, an actual reduction in food production as meat processing plants run out of healthy workers.”

A Smithfield worker in Missouri is suing the company in federal court, accusing it of failing to take action to protect employees by altering operations to permit social distancing or providing personal protective equipment, and of discouraging employees from staying home while ill. A preliminary hearing has been set for later this week in the lawsuit, which does not identify the worker who filed it. A judge has ordered Smithfield to comply with CDC and OSHA guidelines in the interim.

A union leader representing 3,400 workers at a JBS beef plant in Colorado where five workers have died said she fears working conditions that contributed to the spread of the coronavirus among workers will worsen.

“If these meat plants can’t be held liable, there is no reason for them to take measures to ensure workers are safe,” said Kim Cordova, president for workers at the plant in Greeley, Colo. “If workers stop showing up, what are they going to do? Enact a draft? This is insane. If these workers are essential, protect them. They are treating workers like fungible widgets instead of human beings.”

Jeff Stein contributed to this report.