Senate Minority Leader Charles Schumer (D-NY) and Senate Finance Committee ranking member Ron Wyden (D-OR) this week called on the IRS to examine whether the National Rifle Association should lose its tax-exempt status.

The letter cites an investigative report by Senate Finance minority staff into a 2015 NRA delegation trip to Moscow and questions about whether certain NRA activities and interactions with Russian officials violated the NRA’s social welfare requirements as a 501(c)(4) tax-exempt entity. The report also raises concerns about potential private inurement and use of tax-exempt resources for activities unrelated to the group’s exempt purpose, Schumer and Wyden said.

“Given this report’s concerning findings and other allegations of potential violations of tax exempt law by the NRA, it is incumbent on the IRS to fully investigate the organization’s activities to determine whether the NRA’s tax exemption should be disallowed,” Schumer and Wyden said.

An attorney for the NRA refuted the findings in Wyden’s report in a statement to POLITICO and said Schumer and Wyden’s letter is “politically motivated.”

“The exercise should raise concerns about an abuse of government power and waste of taxpayer funds,” said NRA attorney William A. Brewer III. “Fortunately for the NRA and advocacy groups, political speech is protected by the First Amendment of our Constitution.”