The Biden administration brushed off a top GOP lawmaker’s request for information regarding organizations backing pro-Palestinian protests, according to documents obtained by the Daily Caller News Foundation.

Pro-Palestinian protests and riots have surged throughout the country for months, most recently at the Democratic National Convention (DNC) in Chigaco this week. Republican Sen. Joni Ernst of Iowa and 15 other senators wrote to the IRS Commissioner Daniel Werfel in May urging the agency to open an investigation into nonprofit organizations supporting certain pro-Palestinian groups and movements, and whether those organizations’ support jeopardized their tax-exempt status.

Ernst requested a response from Werfel by the end of May. But Werfel did not respond to Ernst’s letter until August, informing her that the agency would follow “standard procedure” and forward her request to the relevant office for review, according to a letter obtained by the DCNF. Werfel noted that “a referral does not necessarily mean we will conduct an examination.”

Werfel told Ernst that the IRS could not “[disclose] any action we may or may not take on a referral; therefore, we are prohibited from commenting on a specific taxpayer and their tax information without authorization and cannot disclose any actions we may take on this information,” further noting that Ernst could reach out with more information by contacting an agency public customer service contact, according to the letter.

This prompted Ernst to write back to Werfel on Thursday that his response was “insufficient and insulting.”

“The tone and brevity of your interim response is troubling, leaving us questioning the value of the information you provided and how serious your office takes oversight inquiries… The IRS continuously fails to serve Americans promptly,” Ernst wrote to Werfel in a letter obtained by the DCNF. “If the IRS policy is to direct United States senators to publicly accessible toll-free numbers and email inboxes, the funds Congress appropriates to the IRS Office of Legislative Affairs each year is clearly being wasted and in need of reprogramming.”

“Rather than sharing what the IRS is doing to enforce our tax laws, your staff’s interim response flatly ignored the substance of our letter,” Ernst wrote to Werfel. When [nonprofit] entities throw their lot in with criminal organizations like Hamas, it is your responsibility to enforce tax law, without partisanship. Unfortunately, you are not honoring your duty in this manner.”

Ernst requested that Werfel answer how many investigations have been opened into nonprofit organizations supporting pro-Palestinian movements, and whether any of those investigations had resulted in the IRS revoking those organization’s tax-exempt status. She further inquired whether it was “standard policy” for the IRS to refer congressional requests to generic customer service contacts.

“When you testified in front of the Senate Finance Committee, you stated, ‘Public trust requires transparency, collaboration with oversight entities such as Congress, adherence to the rule of law, and responsible stewardship of taxpayer dollars,’” Ernst wrote to Werfel. “Your agency’s two responses to our letter indicate the tone you have set at the IRS is fundamentally at odds with this sentiment.”

The IRS did not immediately respond to a request for comment.