In March, Senate Intelligence Committee Chairwoman Dianne Feinstein (D-CA) accused CIA Director John Brennan of spying on the Senate while the agency was facing an investigation over their tactics during the Bush-era. Brennan called Feinstein’s accusations “spurious” and insisted that “nothing could be further from the truth.” On Thursday, he took it all back.

A statement from Brennan’s office released on Thursday confessed that CIA operatives “acted in a manner inconsistent with the common understanding” between Congress and the spy agency. The statement offered congressional investigators an apology for the offense, but that was not good enough for Sen. Mark Udall (D-CO).

“From the unprecedented hacking of congressional staff computers and continued leaks undermining the Senate Intelligence Committee’s investigation of the CIA’s detention and interrogation program to his abject failure to acknowledge any wrongdoing by the agency, I have lost confidence in John Brennan,” Udall said in a statement released on Thursday.

Later, Udall called for Brennan to resign his post. “CIA needs to acknowledge wrongdoing,” the Centennial State senator said, “that simply hasn’t occurred under Brennan’s leadership”

Udall is not the only individual on the left demanding Brennan resign.

“The National Security Agency and the Central Intelligence Agency have been allowed to lie brazenly to Congress, the courts and the public for far too long,” The Guardian’s Trevor Timm wrote. “It’s far past time the Obama administration to bring a little accountability to the intelligence community. It’s time for Barack Obama to fire John Brennan.”

“Brennan’s initial public statements about this scandal severely undermine his credibility. He owes the public a full accounting,” Mother Jones reporter David Corn agreed. “If he remains in the job, President Barack Obama will owe the public an explanation for why he retained an intelligence chief who misled the public about CIA misconduct.”

If this snowballs, the president’s hand may be forced. After all, for how long can Obama afford to frustrate and dispirit his base of support in a tough election cycle?