A major whistleblower advocacy group urged the Securities and Exchange Commission Monday to extend public comment period on the agency’s planned changes to its whistleblower program so that it can glean more information on what the group says are “radically anti-whistleblower” positions in the SEC’s plan that mirror U.S. Chamber of Commerce views.

The comment period ends Tuesday.

The National Whistleblower Center argued Monday in a letter to SEC Chairman Jay Clayton that the agency has yet to release all the materials it sought in a recent Freedom of Information Act request.

The center had asked for, among other items, communications between the SEC and the U.S. Chamber of Commerce in a FOIA request filed July 18, shortly before the SEC proposed the changes on July 20.

However, the SEC has failed to produce 15,877 emails and other documents it identified as responsive to the request, the center said, arguing for more transparency.

The FOIA request was aimed at identifying lobbying efforts by regulated Wall Street companies and the chamber that could have shaped the SEC’s proposed rules, according to a statement from the group.

The list of communications includes 1,078 emails that reference both “whistleblower” and “Chamber of Commerce” sent to the SEC between Jan. 2, 2017, and June 29, 2018, according to the center.

The group has expressed concern that part of the proposed language for the program will curtail whistleblowers’ rights. These issues include a “cap” on recoveries in large fraud cases and impediments to reward recovery by an analyst after his or her whistleblower disclosures to the SEC, it said.

The SEC “appears poised to be the first agency to ever adopt this discredited and highly destructive Chamber of Commerce proposal,” the Center’s letter alleged, basing its accusation on public comments SEC commissioners had previously made.

The group wrote that there is “a compelling need for full and complete transparency as to why the [SEC] proposed this rule, and what lobbying efforts were behind the proposals.”

“The materials NWC requested are imperative to the public’s understanding of the reasoning behind the proposed rule, the impact it will have on the whistleblower program, and the influence the Chamber of Commerce and other members of the regulated community had on this rulemaking,” the center stated in its letter to Clayton.

A spokesperson for the SEC declined comment on the extension date request.