Two weeks after the Department of Education abruptly cut off the Consumer Financial Protection Bureau from student loan data, several congressional Democrats are asking Secretary Betsy DeVos to explain what happened.

A total of 39 senators and representatives wrote to DeVos on Thursday asking for an explanation of the decision, and who the agency may have worked with before reaching it.

"[W]e are deeply concerned this backward step will allow student loan servicers to more easily take advantage of borrowers," wrote the Democrats, including Sen. Sherrod Brown of Ohio, the ranking member of the Banking Committee, and Rep. Maxine Waters, his counterpart in the House.

Education officials had justified the decision to end data sharing with the CFPB on the grounds that the bureau, led by Obama appointee Richard Cordray, had overstepped its jurisdiction and sowed confusion among loan servicers.

The Democrats called those assertions "false," and sought to have DeVos answer for them. The bureau does have authority to protect student borrowers from fraud, they said.

For his part, Cordray has asked the Education Department to resume working with his bureau.