Those charges are detailed in a letter to Pruitt and attached to a separate letter to Trump.

In discussions with the lawmakers, Kevin Chmielewski, onetime deputy chief of staff for operations at the EPA, confirmed many of the details of those reports, which were previously attributed to unnamed sources. He also leveled new charges of "wasteful spending, unethical behavior and improper retaliation against EPA staff" on the part of Pruitt.

Pruitt has been under fire following revelations that he rented a Capitol Hill condominium linked to an energy lobbyist whose firm had business before the Environmental Protection Agency. That sparked a series of leaks to news agencies that alleged the EPA purged the administrator's critics and expanded on previous reports of Pruitt's high spending .

In one of the letters, the five lawmakers urge President Donald Trump to "hold Administrator Pruitt accountable for his serious ethical lapses and to restore honest, competent leadership to EPA so that this important agency may fulfill its critical mission."

Democratic lawmakers on Thursday released a pair of letters detailing pages of allegations leveled at embattled EPA Administrator Scott Pruitt by a longtime Trump staffer who was reportedly sidelined for questioning Pruitt.

Among the charges, Chmielewski disputes Pruitt's claim in a Fox News interview that he was unaware someone at the EPA went behind the White House's back to orchestrate a pay raise for two of his close aides. The raises were "100% Pruitt himself," Chmielewski told the lawmakers.

EPA chief of staff Ryan Jackson has since taken responsibility for approving the raises. Chmielewski suggests Jackson has long been aware of management issues at the EPA, alleging Jackson told him "the nightmare is now yours" when he took his post at the agency.

The former Trump campaign aide also claims he overheard a conversation between Pruitt and energy lobbyist Steven Hart, in which Hart complained that Pruitt had failed to pay rent on the condo at the center of the controversy and that his daughter had damaged the apartment.

Pruitt faces claims that he broke his lease by allowing his family to stay in the apartment. Last week, an EPA watchdog walked back his finding that Pruitt's housing arrangement did not violate federal gift rules, saying he had not investigated whether Pruitt stuck to the terms of his lease.

Chmielewski also claims that Pruitt, who is under investigation for running up hefty travel bills, arranged trips under the auspices of official business in order to tour cities or countries he wanted to visit or to return to his home state of Oklahoma.

The EPA did not immediately return a request for comment.

The letter ends with a request to the EPA for 19 documents related to the charges.

They were signed by Senate Democrats Thomas Carper of Delaware and Sheldon Whitehouse of Rhode Island, as well as Democratic House members Elijah Cummings of Maryland and Gerald Connolly and Donald Beyer of Virginia.

The Democrats suggest Trump does not have all the relevant facts given his recent statements about Pruitt, apparently referencing a tweet this past weekend, in which the president attempted to justify Pruitt's spending and said, "Scott is doing a great job!"

@realDonald Trump: While Security spending was somewhat more than his predecessor, Scott Pruitt has received death threats because of his bold actions at EPA. Record clean Air & Water while saving USA Billions of Dollars. Rent was about market rate, travel expenses OK. Scott is doing a great job!

The lawmakers urged Trump "to conduct your own investigation of Administrator Pruitt's actions, including examining relevant documents and speaking with credible witnesses such as Mr. Chmielewski."

Read the full letter to Trump here.