By Nate Raymond
May 20 (Reuters) - A California-based Tea Party group sued the U.S. Internal Revenue Service on Monday in what marked the first lawsuit to stem from an investigation finding the agency singled-out conservative organizations.
In a lawsuit filed in U.S. District Court in Cincinnati, the NorCal Tea Party Patriots accused the IRS of violating its constitutional rights due to the "intensive and intrusive scrutiny" it received while seeking tax-exempt status.
The lawsuit sought class action status on behalf of all conservative and libertarian groups - such as those associated with the Tea Party movement - that were targeted by the IRS for extra scrutiny from March 2010 through the middle of this month. Tea Party groups call for reduced federal spending and taxation.
The lawsuit has the backing of a group calling itself Citizens for Self-Governance, a group launched by the co-founder the Tea Party Patriots, Mark Meckler.
"We stand shoulder to shoulder with all those known and unknown who have been abused by a federal government run amok," Meckler said in a statement.
Representatives of the IRS did not respond to a request for comment Monday after normal business hours.
The lawsuit came as the Senate Finance Committee and House of Representatives Oversight and Government Reform Committees prepared to hold hearings on the IRS scandal, which cost acting IRS commissioner Steven Miller his job last week.
Lois Lerner, chief of the IRS tax-exempt unit, was set to testify Wednesday before an investigative committee of the House of Representatives, along with other officials.
A White House spokesman told reporters Monday that two senior aides to President Barack Obama knew weeks ago about a report by the U.S. Department of Treasury's Inspector General for Tax Administration about the IRS's targeting of conservative groups.
The lawsuit was filed in Cincinnati, home to the field office at the center of the storm, by the NorCal Tea Party Patriots, a group based in Colfax, California.
On its website, NorCal says its volunteers "simply love their country and want to save it from a tyrannical takeover." (http://www.norcalteaparty.com)
In the lawsuit, NorCal said it had first sought tax-exempt status in March 2010. The group said due to an "unjustifiable delay," it did not receive approval for tax-exempt status until Aug. 2, 2012.
"The IRS engaged in a tactic of suffocating NorCal Tea Party Patriots and other similarly situated groups with requests that were so searching and extensive that they would have presented a serious challenge even for sophisticated businesses," the complaint said.
The lawsuit seeks unspecified monetary damages for the IRS's alleged violation of the Privacy Act of 1974 and the First and Fifth Amendments of the U.S. Constitution.
Exactly how many groups could qualify to be members of the class if a federal judge certified it is unclear. The inspector general's report reviewed 296 applications. (Reporting by Nate Raymond in New York)