Amid outcry over revelations that Internal Revenue Service specialists specifically targeted conservative groups for scrutiny before the 2012 elections, President Barack Obama said Monday that the tax agency employees' reported conduct was "outrageous" and "contrary to our traditions."
Appearing at a White House press conference with British Prime Minister David Cameron, the president said he does not want to judge the findings of an Inspector General investigation "prematurely" but said that if the reports of political targeting are found to be correct, those responsible must be held "fully accountable."
"If in fact IRS personnel engaged in the kind of practices that have been reported on and were intentionally targeting conservative groups, then that’s outrageous and there’s no place for it," he said.
"I've got no patience with it," he added. "I will not tolerate it and we will make sure that we find out exactly what happened on this."
Reports surfaced Friday that an IRS official had apologized for the targeting by staffers in a Cincinnati field office, which singled out groups for additional review if they included the words "tea party" or "patriot" in their applications for tax-exempt status.
A partial draft report from the Treasury Inspector General for Tax Administration -- obtained by NBC News -- shows that top officials knew about the targeting nearly a year before then-IRS Commissioner Douglas H. Shulman, who was appointed by President George W. Bush, testified to Congress in March 2012 that no singling out of conservative groups ever occurred.
The House Ways and Means Committee announced after the president's remarks that it will hold a hearing on the alleged targeting on Friday, May 17. Acting IRS Commissioner Steve Miller and J. Russell George, the Inspector General who headed up the IRS report, are expected to testify.
And the IRS confirmed Monday night that Miller was informed in May of last year that "some specific applications were improperly identified by name and sent to the [IRS] Exempt Organizations centralized processing unit for further review."
In a statement earlier Monday, White House spokesman Jay Carney said the president is “concerned” about the reported conduct of “a small number of Internal Revenue Service employees.”
“If the Inspector General finds that there were any rules broken or that conduct of government officials did not meet the standards required of them, the President expects that swift and appropriate steps will be taken to address any misconduct," Carney said.
Lawmakers on both sides of the aisle have called for extensive investigation into the IRS practices.
In a letter to Treasury Secretary Jack Lew, Republican Sen. Marco Rubio of Florida called for the resignation of Acting Commissioner Miller, who previously served as Shulman’s deputy.
"[I]t is clear the IRS cannot operate with even a shred of the American people's confidence under the current leadership," Rubio wrote. "I strongly urge that you and President Obama demand the IRS Commissioner's resignation, effectively immediately. No government agency that has behaved in such a manner can possibly instill any faith and respect from the American public."
Top Senate Republican Mitch McConnell went further, calling the burgeoning IRS scandal "just one example of an administration-wide effort to silence critics."
"The Obama effort to shut up opponents isn't limited to the IRS," he told conservative outlet Breitbart News. "It applies to the FCC [Federal Communications Commission], SEC [Securities and Exchange Commission], FEC [Federal Elections Commission], HHS [Department of Health and Human Services]."
A McConnell spokesman told NBC News that the senator was specifically referring to those agencies’ attempts to implement rules requiring that third-party groups and businesses disclose donors or political activities.
Senate Finance Committee Chairman Max Baucus, a Democrat, also called the targeting "intolerable" and an "outrageous abuse of power."
And Senate Majority Leader Harry Reid also weighed in, saying the allegations would represent a "terrible breach of the public trust" and pledging that the chamber will "quickly take appropriate action" based on the inspector general's findings.
NBC's Kelly O'Donnell, Luke Russert and Mark Murray contributed to this report.