BOSTON (AP) — A group of Democratic members of Congress, led by Sen. Edward Markey of Massachusetts, is seeking reassurances that workers at hospitals owned by Steward Health Care will have their health care and retirement benefits protected.

Steward last month said it plans to sell off all its hospitals after announcing that it filed for bankruptcy protection.

In a letter to acting Labor Secretary Julie Su on Monday, Markey said Steward’s bankruptcy “poses concerns for the nearly 30,000 workers including nearly 10,000 in Massachusetts, who rely on Steward Health Care for their paychecks, health care plans, and retirement benefits.”

“We write to ask that the U.S. Department of Labor ensure that Steward workers and retirees receive the health care and retirement benefits to which they are entitled. Workers and retirees must be protected from further harm resulting from Steward’s gross financial mismanagement,” Markey wrote.

Representatives of Steward did not immediately respond to an email seeking comment on what steps, if any, the company has taken to ensure workers receive their benefits.

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The Dallas-based company, which operates more than 30 hospitals nationwide, has said it does not expect any interruptions in its hospitals’ day-to-day operations throughout the Chapter 11 process.

Markey said many workers who rely on Steward Health Care for their livelihood are already facing financial uncertainty and anxiety. In Massachusetts, he said, paychecks to Steward workers were delayed following the bankruptcy filing due to processing delays.

Markey and the other lawmakers are asking the Department of Labor to take steps to protect workers, including determining Steward’s plan for continuing benefits during bankruptcy as well as in the event of a facility’s closure or buyout and making sure health claims are paid throughout the bankruptcy process.

“Although the responsibility for this crisis rests exclusively on Steward and its corporate collaborators, a resolution to this crisis that protects workers, patients, and communities demands involvement and collaboration among federal, state, and local authorities,” Markey said in the letter.

In addition to Massachusetts, Steward employs workers in Arizona, Arkansas, Florida, Louisiana, Ohio, Pennsylvania and Texas.

The letter was also signed by Democratic Sens. Sherrod Brown of Ohio and John Fetterman of Pennsylvania and independent Sen. Bernie Sanders of Vermont. Democratic Reps. Ayanna Pressley, Stephen Lynch, James McGovern and Seth Moulton, all of Massachusetts, and Rep. Sheila Jackson Lee from Texas also signed the letter.