Tom Carper of DE and Sheldon Whitehouse of Rhode Island, said in a letter Tuesday to Senate Environment and Public Works Chairman John Barrasso (R-Wyo.) that they were provided with an internal EPA document that said a threat assessment did not justify such expenses.
Separately, Reps. Bonnie Watson Coleman, D-12th Dist., and Albio Sires, D-8th Dist., were among 64 House Democrats signing a letter to Trump calling him to dismiss Pruitt.
Congressional Republicans are standing by Environmental Protection Agency chief Scott Pruitt as he fends off a barrage of ethics troubles, a testament to their support for his agenda and reluctance to wade into a nasty confirmation fight over who might replace him.
The Republican-led House Oversight committee confirmed Monday it has expanded its review of Pruitt's travel spending to address questions surrounding his bargain $50-a-night rental of a Capitol Hill condominium tied to a fossil fuels lobbyist.
President Donald Trump has defended Pruitt, downplaying the ethical questions swirling around his embattled EPA chief while commending his work at the agency. That amount includes travel and overtime pay for Pruitt's round-the-clock detail of security officers.
The same February assessment described repeated efforts by EPA intelligence officials to tell the agency's inspector general and senior leadership "that "the threat" to the Administrator was being inappropriately mischaracterized" by Pruitt's security detail, Whitehouse wrote in the letter, sent jointly with Sen. Senate Democrats sought to undercut that argument Tuesday, citing a recent internal EPA analysis that concluded "EPA Intelligence has not identified any specific, credible, direct threat to the EPA administrator". Barrasso said he saw the positive impact of Pruitt's actions late last month as he and Pruitt toured a Wyoming coal mine.
"His actions have jeopardized EPA's ability to protect human health and the environment, and the only way to regain the American people's trust in EPA is for Pruitt to resign immediately".
Jahan Wilcox, an EPA spokesman, said in a statement to CNN that "Administrator Pruitt does not have a challenge coin", adding, "but while we're on the subject, President Obama's Assistant Secretary of Veterans Affairs Tammy Duckworth spent taxpayers dollars on challenge coins".
As Pruitt struggled to keep his job, another battle was brewing in the Senate, where Schumer vowed to oppose Trump's nomination of former coal industry lobbyist Andrew Wheeler as the EPA's No. 2 official.
A nationwide search of state and federal court records by AP found no case where anyone has been arrested or charged with making violent threats against Pruitt.
The agency's inspector general initiated a criminal investigation after protesters crashed a speech Mr. Pruitt was giving at the Mayflower Hotel in Washington last spring, but the Justice Department has repeatedly declined to prosecute cases, at times citing freedom of speech provisions of the United States Constitution, agency records show.
Wilcox told CNN Wednesday the agency will respond to the committee.