Watchdog groups press embattled EPA chief Pruitt for transparency on legal defense fund Pruitt said last month that a legal defense fund had been set up.

Lawmakers and watchdog groups pressed Environmental Protection Agency Administrator Scott Pruitt Thursday to share details about his legal defense fund.

The EPA administrator told a Senate hearing last month that a legal defense fund has been set up to help with his mounting legal fees as he grapples with a growing number of federal ethics investigations, including ones looking into whether Pruitt directed EPA aides to help him with personal errands or whether he broke rules prohibiting using his office for personal gain.

A month has passed since Democratic Sens. Chris Van Hollen, Thomas Carper, Tom Udall, and Sheldon Whitehouse gave Pruitt 10 days to provide them with basic information about the legal defense fund, but the senators told ABC News that Pruitt has yet to respond.

Government watchdog groups, including Public Citizen, Common Cause, Democracy 21, Every Voice and the Sunlight Foundation, released a letter Thursday urging the administrator to comply with the request.

Democrats have few options to compel Pruitt to produce the material, as they are in the minority in Congress and would be unlikely to get GOP cooperation to such a move. They could try to sue the Administrator for the information in court, but that option is rarely used. Groups outside of Congress could also try to sue for the information.

Your browser does not support iframes.

“There remains no record of the operations and fundraising of your legal defense fund,” the letter said. “If a legal defense fund is not carefully set up and administered, there are many ways the Fund may run afoul of executive branch ethics rules. Given the large number of ethics scandals now under investigation at the EPA, further scandals should be avoided by you and the agency.”

Jahan Wilcox, an EPA spokesman, referred questions to Pruitt's outside counsel. Pruitt’s outside attorney has not responded to requests from ABC News for comment.

At last month’s Senate hearing, Pruitt said that he would follow proper procedures for the fund, including not accepting money from industries that have business before the EPA. But he has shared very little else about the fund, including its name, structure, fundraising activities and the identities of his contributions.

“The same way Scott Pruitt never came clean on the dark money forces that funded him as Oklahoma Attorney General – which have unknown business before the EPA – refusing to disclose legal fund donors is another avenue for graft and influence," Whitehouse said in a statement to ABC News.

In the letter, the watchdog groups said that the Office of the Government Ethics legal defense funds has offered little guidance on how executive branch personnel should operate, allowed very little transparency on how the funds are being managed and whether such funds are complying with the ethics rules.

Several former members of the Trump administration have formed legal defense funds to deal with expenses related to the special counsel investigation into possible election interference. President Donald Trump formed “the Patriot Legal Expense Fund Trust LLC,” to help support any individual who “was an employee, consultant, fundraised or volunteer” on behalf of President Trump’s campaign. In doing so, attorneys for the president identified the rules that would govern contributions to avoid potential conflicts of interest.

"These legal defense funds represent a crisis in the administration – not just in terms of the number of ethics scandals, but also in the fact that there are very few rules governing how these legal defense funds are created and operate," Public Citizen government affairs lobbyist Craig Holman said.

"If these funds are left unregulated, they provide an ideal opportunity for wealthy special interests and corporations to attempt to buy favors from government officials," Holman added. "Any official who is facing serious legal charges will undoubtedly be most grateful to any person or company who chips in a large amount of money to pay for his or her legal defense."