A growing number of conservative leaders and GOP lawmakers are voicing their support for Environmental Protection Agency Administrator Scott Pruitt amid some calls for him to resign.

The Conservative Action Project released a letter Friday with 113 signatures of conservative leaders calling on President Donald Trump to keep Pruitt in the administration.

“Conservatives stand behind Scott Pruitt as administrator of the Environmental Protection Agency … and thank him for the significant actions he has taken to implement President Trump’s deregulatory agenda,” the letter read. “President Trump campaigned on reducing Washington’s bureaucracy, and Administrator Pruitt has been instrumental to that effort.”

Signatories included American Legislative Exchange Council CEO Lisa Nelson, Judicial Watch President Tom Fitton, former Sen. Jim DeMint of South Carolina, former Virginia Attorney General and Senate Conservatives Fund President Ken Cuccinelli, and Citizens United President David Bossie.

Another group, CNP Action, sent a letter directly to Trump on Friday, praising Pruitt’s actions at the EPA.

“We write to thank you for your ongoing support of EPA Administrator Scott Pruitt and to add our names to a growing list of people who recognize him as a capable administrator who is finally reining in the EPA and restoring its core mission,” CNP Action’s letter read.

The letter was signed by CNP Action Chairman William L. Walton, former Attorney General Edwin Meese III, Family Research Council President Tony Perkins, Heritage Action for America CEO Michael A. Needham, FreedomWorks President Adam Brandon, Media Research Center President L. Brent Bozell III, Tea Party Patriots Citizens Fund Chairman Jenny Beth Martin, former U.S. Rep. Bob McEwen of Ohio, Club for Growth President David McIntosh, and former Ohio Secretary of State J. Kenneth Blackwell, chairman of the Constitutional Congress Inc. (Walton is a Heritage Foundation trustee and Meese is the think tank’s Ronald Reagan distinguished fellow emeritus.)

Most of the letter’s signatories added their names to the Conservative Action Project letter as well.

The Congressional Western Caucus also released a statement in support of Pruitt with remarks from Congressional Western Caucus Chairman Paul A. Gosar, R-Ariz.; House Science, Space, and Technology Committee Chairman Lamar Smith, R-Texas; House Committee on Appropriations subcommittee on interior, environment, and related agencies Chairman Ken Calvert, R-Calif.; and Western Caucus members Reps. Doug LaMalfa, R-Calif.; Louie Gohmert, R-Texas; and Markwayne Mullin, R-Okla.

“EPA Administrator Pruitt has proven himself one of the most effective Cabinet members in the Trump administration,” Gosar said in a statement. “His track record on energy, the environment, deregulation, the rule of law and science-based decision-making is exceptional. Because he is an important part of the ‘Make America Great Again’ agenda, it should come as no surprise that a lynch mob of opportunistic politicians and certain members of the media are doing everything they can to attempt to remove him from office.”

The outpouring of support came amid new calls on Pruitt to step down from his post. The EPA chief has faced criticism for his first-class travel, Washington living arrangements, and staff salaries. Pruitt, in interviews with The Daily Signal and Fox News this week, defended his actions and said he is taking steps to correct problems at the agency.

For some lawmakers, including three Republican members, that’s not enough. This week, Reps. Elise Stefanik of New York, and Carlos Curbelo and Ileana Ros-Lehtinen of Florida called on Pruitt to step down.

House Minority Leader Nancy Pelosi, D-Calif., announced Friday that she also wants Pruitt to resign, claiming he has brought a “culture of corruption, cronyism and incompetence” to the EPA.

Trump has continued to support Pruitt, tweeting Friday that the EPA administrator “is doing a great job.”