Speaking to reporters during a press call, Clinton campaign chairman John Podesta called Comey's decision to tell lawmakers an "extraordinary step."
"The more information that comes out, the more overblown this all seems and the more concern it creates about Director Comey's actions," Podesta said.
He criticized Comey's decision to provide "selective information" in the announcement, which "allowed partisans to distort and exaggerate in order to inflict maximum political damage."
Podesta described Comey's letter as "long on innuendo and short on facts."
"It's now up to him, who owes the public answers to the questions that are now on the table, and we're calling on him to come forward and give those answers to the American public," Podesta said.
Clinton campaign manager Robby Mook said that Comey's announcement had created "an urgency" so close to Election Day.
"He owes the public the full story, or else he shouldn't have cracked open this door in the first place," Mook said.