The Republican National Committee marked Tax Day by suing the Internal Revenue Service.

The lawsuit charges that the IRS is withholding records sought by the RNC’s May 2013 Freedom of Information Act (FOIA) request, in which the committee sought to review documents and correspondence related to criteria used for reviewing and approving 501(c)(4) tax-exempt organizations.

The FOIA request seeks all documents dated between Jan. 1, 2010, and May 20, 2013, containing the words “tea party,” “patriot,” and/or “9/12 project,” referring to the group created by Glenn Beck, along with any documents pertaining to increased scrutiny of 501(c)(4)s, especially using “be on the lookout for” criteria.

Submitted by associate counsel Jonathan Waclawski, the FOIA letter requests “a similar quick response as Pro Publica received.” ProPublica revealed last May that, in its request to see the applications of 67 nonprofits, the IRS gave them confidential information on conservative groups.

That’s left the IRS with 226 business days, by the RNC’s count, to fulfill the request. The committee said the agency “requested several extensions in order to complete the RNC’s request, but has yet to present the information.”

“The RNC believes the undue delay in producing the requested documents is unacceptable and inexcusable, given that many of these documents have been already produced to other requesting entities. Release of the requested documents is in the public interest, as Americans deserve to know how the IRS interprets and enforces the tax laws—and why it would deliberately target people because of their values and beliefs,” the RNC said in a statement.

The filing in the U.S. District Court for the District of Columbia details numerous letters over the past year in which in the IRS told the RNC that it was still trying to locate the requested information. A letter dated Jan. 16 said, “I will contact you by April 18, 2014, if I am still unable to complete your request.”

RNC Chairman Reince Priebus said the party filed suit “because the Obama administration has a responsibility to be transparent and accountable to the American people.”

“The IRS has a legal obligation to answer our inquiry for these records. On Tax Day especially Americans deserve to know whether they can trust the agency to which they’re sending their taxes,” Priebus said.

“If the IRS and the Obama administration don’t have anything to hide, why not answer the request? Their delays and distractions make Americans think they’re trying to cover up their actions, just like ex-IRS employee Lois Lerner. We’re going to keep fighting to hold the IRS and Obama administration accountable because Americans deserve a government that treats them fairly and not one that harasses them because of their beliefs nor an administration that goes after its perceived political enemies.”