Sen. Richard Blumenthal (D-Conn.) questions a witness during a hearing this month. (T.J. Kirkpatrick/Bloomberg)

Nine Senate Democrats, led by Richard Blumenthal of Connecticut, called Friday for an investigation into a questionnaire sent by the Trump transition team to the Energy Department, asking for names of “employees or contractors” who attended United Nations climate change meetings under President Obama.

The questionnaire was disavowed Wednesday by the Trump transition, which released a statement that it was “not authorized or part of our standard protocol” and that the individual who sent it had been “properly counseled.”

But the lawmakers still want the U.S. Office of Special Counsel to investigate the incident, saying the questions asked “appear to have violated long-standing federal laws designed to protect civil servants against coercion for partisan purposes.” They cite the Civil Service Reform Act of 1978, which created a merit system for the promotion and advancement of federal employees, and, the senators wrote, “establishes that employees should be protected” against partisan pressures.

Their move appeared to escalate the controversy surrounding the questionnaire and the fears it stoked among scientists about how the incoming administration will treat their research, particularly on the most hot-button issues like climate change.

In their letter, the Democratic senators cited not only the question about employees who attended climate change meetings internationally but also a request for a list of “all Department of Energy employees or contractors who have attended any Interagency Working Group on the Social Cost of Carbon meetings,” and a “list of the top 20 salaried employees” at various national laboratories.

“Taken together, these questions seem to demonstrate a clear intent to retaliate or discriminate against federal employees,” the letter states.

The Office of Special Counsel, headed by special counsel Carolyn Lerner, protects federal employees and whistleblowers. It polices “prohibited personnel practices,” which, when it comes to politics in particular, include the following, according to the agency: “An employee cannot be pressured into political activity by a superior. This section also prohibits retaliation against an employee for refusing to engage in political activity.”

The senators suggest that the questionnaire may constitute a prohibited personnel practice because its questions “appear to be motivated by partisan political purposes” — to challenge Obama policies on climate change and to identify those staffers who participated in or implemented them. The group also is asking for an investigation of whether any similar questionnaires have been sent to other federal agencies.

Other agencies involved in U.S. climate policy include the State Department, the Environmental Protection Agency and the Interior Department. Scientists at NASA and the National Oceanic and Atmospheric Administration also conduct considerable research related to climate change.

The Trump transition team, by email Friday afternoon, reiterated its prior statement that the questionnaire in question was “not authorized.”

Debra Katz, a civil rights attorney with Katz, Marshall and Banks, said she considered the Democrats’ request “appropriate.” She noted that the transition team’s intention is “crucially important, but it feels very McCarthyite in nature, in trying to put together a list of people.”

From the perspective of the Office of Special Counsel, Katz said, the fact is that the Trump transition team does not yet control the Energy Department and so it isn’t implementing personnel practices. Nor has any action yet been taken against any employee as a result of the questionnaire. The Energy Department ultimately refused to provide any names to the transition team.

“If actions were taken against any of these people, because of their political activities either outside of work or because they engaged in climate change work in their official capacities, it would in my view be a clear violation of the law and would be a prohibited personnel practice,” she said.

J. David Cox Sr., president of the American Federation of Government Employees said the union welcomed the call for an investigation. “Our laws were designed to protect civil servants from political intimidation and retaliation,” he said in a statement, “and any attempt to circumvent these laws must be fully investigated and appropriately addressed.”

But Robert Henneke, the general counsel of the Texas Public Policy Foundation, a conservative group, had a different response to the Democrats’ move.

“Every American, including federal employees, have a right to their own [personal] viewpoints,” he said in a statement. “But, executive branch federal employees owe an obligation to be faithful in executing the policies and direction of the next Administration. For those that will not, they should find employment elsewhere.”