James Dennehy, who led the FBI’s largest field office, was forced to resign after resisting efforts by the Trump administration to identify agents involved in Jan. 6 prosecutions. Sources familiar with the situation say Dennehy was given a choice — resign or be fired.

Dennehy’s dismissal follows his response to a Justice Department request for a list of FBI personnel involved in cases against Trump supporters linked to the Jan. 6 protests. In an internal email, he urged his staff to “dig in,” warning that fellow agents were being removed for simply doing their jobs — which actually wouldn’t warrant such secrecy.

The move is part of a broader shake-up within the FBI, where multiple senior officials have been removed. Among them were eight high-ranking agents tied to high-profile cases against Trump. Dennehy’s refusal to comply reportedly delayed mass firings of bias and corrupt employees that were expected to take place earlier.

Dennehy also played a key role in the federal corruption investigation into New York City Mayor Eric Adams. Those charges were dropped after prosecutors resigned in protest, accusing the Trump administration of political interference.

In his farewell email, Dennehy urged FBI employees to remain committed to their mission and not allow political pressure to dictate their work. He wrote that he would “never stop defending” the integrity of the bureau, even if it had to be done “from outside the wire.”

Dennehy, a former Marine, spent decades with the FBI, holding leadership positions in Washington and New York before taking over the New York field office last year.