Democratic lawmakers are urging the State Department's Inspector General to probe the department's personnel practices after several employees voiced concerns their careers were being stalled because of their past work under the Obama administration.

"Our staffs have been made aware of credible allegations that the State Department has required high-level career civil servants, with distinguished records, serving administrations of both parties, to move to performing tasks outside their area of substantive expertise," the Ranking Democrat on the House Foreign Affairs Committee Eliot EngelEliot Lance Engel Overnight Cybersecurity: Tech execs testify on countering extremist content | House approves cyber diplomacy bill | Pentagon reportedly mulling nuclear response to cyberattacks House votes to restore State cyber office, bucking Tillerson Overnight Cybersecurity: Bipartisan bill aims to deter election interference | Russian hackers target Senate | House Intel panel subpoenas Bannon | DHS giving 'active defense' cyber tools to private sector MORE (D-N.Y.) and the Ranking Democrat on the House Oversight Committee Rep. Elijah CummingsElijah Eugene Cummings Top committee Dems: GOP chairs trying to undermine Russia probe with FBI texts Dems want answers on White House security clearance process House Oversight slams TSA after report says officials 'interfered' in disciplinary case MORE (D-Md.) said in a letter obtained by CNN.

"At the very least, this is a waste of taxpayer dollars. At worst it may constitute impermissible abuse and retaliation."

CNN first reported on Friday that several employees in the department were increasingly frustrated after they returned to State from high-level assignments only to be put on low-level jobs such as responding to Freedom of Information Act (FOIA) requests.

Many of the employees who have been reassigned under Secretary of State Rex Tillerson

Rex Wayne Tillerson Protests erupt in Switzerland ahead of Trump's Davos trip Tillerson's open-ended Syria war proves US is stuck in mideast quicksand Tillerson blames Russia for allowing new Syrian chemical weapons attack MORE had worked in the offices of special envoys created during the Obama administration. Officials who previously worked in those offices, which Tillerson has done away with, have been assigned to clerical tasks they say do not match up with their previous assignments.

Some of these employees claim that they may be victims of political retribution.

State Department spokeswoman Heather Nauert told CNN employees were being assigned to FOIA work out of necessity, and politics had nothing to do with the move to put employees on the FOIA task force.

"There is a job that needs to be done," she said. "It may not be a glamorous job, but it's an important one."

Top Dems demand answers from State Department after employees cite career concerns