Attorney General Loretta Lynch and other senior Justice Department officials made it "abundantly clear" to FBI Director James Comey that his plan to disclose new steps in the investigation surrounding Hillary Clinton's private email server would violate long-standing tradition, sources familiar with the matter told ABC News.
In conversations with FBI counterparts hours before Comey disclosed that the FBI was hoping to review newly-discovered emails possibly "pertinent" to the Clinton probe, Justice Department officials emphasized that the department has long steered clear of taking such investigative actions close to an election if those actions could potentially influence the outcome of an election, sources said.
Justice Department officials were also concerned about the planned disclosure because the FBI had yet to review the newly discovered emails.
"We don't know what this is yet," one source said, noting that authorities are still seeking a judge's approval to start taking a closer look at the emails. No one knows if "there is any 'there' there," the source added.
But Comey "decided to move forward anyway," another source said.
Comey told Congress of the decision in a letter Friday afternoon, later saying he felt compelled to do so because he had previously assured lawmakers and the public that the FBI investigation was "completed."
Investigators came across the emails while looking into a completely separate criminal matter -- former Rep. Anthony Weiner's alleged "sext" messages to an underage girl in North Carolina. Weiner, a Democrat from New York, is married to Huma Abedin, one of Clinton's most trusted aides, and investigators found what Comey described as "emails that appear to be pertinent" to the Clinton probe on at least one electronic device used by both Weiner and Abedin.
On Thursday, investigators briefed Comey on the newly discovered emails, and he agreed that the team working on the Clinton probe should try to review the emails "to determine whether they contain classified information, as well as to assess their importance to our investigation," Comey said in his letter Friday.
"[W]e don't know the significance of this newly discovered collection of emails," Comey wrote to FBI personnel in an internal message later in the day.
It's unclear how long the review process will take, according to Comey.
During a House hearing last month, Comey was asked if he would "re-open" the Clinton investigation if "relevant and substantial" information was uncovered.
If anyone had potentially "new and substantial information, we'd like to see it so we can make an evaluation," he responded.
In a conference call with reporters today, Clinton campaign manager John Podesta said Comey's letter to Congress "allowed partisans to distort and exaggerate in order to inflict national, political damage, and no one can separate what is true from what is not because Comey has not been forthcoming with the facts.”
"The more information that’s come up, the more overblown this all seems and the more concern it creates about director Comey’s actions," Podesta said.
On the campaign trail Friday, Donald Trump applauded what he described as the FBI's decision to "reopen" the Clinton investigation, which had found no charges in the matter were warranted.
"I have great respect for the fact that the FBI and the Department of Justice are now willing to have the courage to right the horrible mistake that they made," the Republican nominee said. "This was a grave miscarriage of justice that the American people fully understood."