President-elect Donald Trump's transition team may have disavowed a questionnaire sent to the U.S. Department of Energy seeking a list of individuals who have worked on climate change policies.

But that did not stop nine Senate Democrats from asking the U.S. Office of Special Counsel to look into whether the questionnaire may have "violated long-standing federal laws designed to protect civil servants against coercion for partisan purposes."

"We ask that you take immediate action to review these deeply troubling requests," the senators — Richard Blumenthal of Connecticut, Patrick Leahy of Vermont, Dianne Feinstein of California, Tammy Baldwin of Wisconsin, Cory Booker of New Jersey, Sheldon Whitehouse of Rhode Island, Benjamin Cardin of Maryland, Christopher Coons of Delaware, and Patty Murray of Washington — wrote Special Counsel Carolyn Lerner in a letter dated Dec. 15.

According to the senators, the requests in the questionnaire, which also sought information about the publications and associations of scientists who work for the DOE's national laboratories, "strongly appear to be motivated by partisan political purposes, which are forbidden by the [Civil Service Reform Act of 1978] and are therefore impermissible actions by transition officials."

The existence of the questionnaire was leaked Dec. 9, prompting environmental advocates to raise alarms that the incoming administration was conducting a "witch hunt" for employees who worked on programs and policies with which they disagree. The DOE has refused to provide the requested information, and CNN has reported that the Trump transition team has attributed the sending of the questionnaire to an individual who has since been "properly counseled."

However, that does not seem to have appeased the nine senators who signed onto the letter urging Lerner to "investigate whether this questionnaire, or any similar questionnaire being circulated by transition officials, violates federal law and hold accountable those responsible."

"In your investigation, we ask you to take a close look at the motives of the transition officials in singling out federal employees for implementing our nation's climate change policies," the senators wrote. "We also ask that you publicly communicate to Congress clear guidance on the circumstances under which the Office of Special Counsel will investigate instances of retaliation or discrimination against career civil servants for implementing the policies of any previous administration."

The senators asked for a response to their request by Dec. 23.