FILE PHOTO: James Comey, former director of the Federal Bureau of Investigation (FBI), is seen in a frame grab from a video feed as he is sworn in remotely from his home during a Senate Judiciary Committee hearing exploring the FBI's investigation of the 2016 Trump campaign and Russian election interference in Washington, U.S., September 30, 2020. U.S. Senate Committee on the Judiciary/Handout via REUTERS/File Photo

By Kanishka Singh, Andrew Goudsward and Sarah N. Lynch

WASHINGTON (Reuters) -The U.S. Justice Department filed criminal charges against former FBI Director James Comey on Thursday, in a dramatic escalation of President Donald Trump's retribution campaign against his political enemies.

If convicted, Comey could face up to five years in prison. He faces charges of making false statements and obstructing a congressional investigation.

Comey, in a video posted on Instagram, said: "My heart is broken for the Department of Justice, but I have great confidence in the federal judicial system, and I'm innocent. So, let's have a trial and keep the faith."

Trump has threatened to imprison his political rivals since he first ran for president in 2015, but Thursday's indictment marks the first time his administration has succeeded in securing a grand jury indictment against one of them. Trump's Justice Department is also investigating other antagonists including New York Attorney General Letitia James and John Bolton, who served as a national security official in Trump's first term as president.

The charges breach decades-long norms that have sought to insulate U.S. law enforcement from political pressures. The federal prosecutor in Virginia who had been tasked with pursuing the case resigned last week after drawing Trump's wrath for expressing doubts about the case, and others in the office have privately said the evidence does not merit criminal charges, according to sources familiar with the matter.

Trump, who has pressured Attorney General Pam Bondi to prosecute Comey and other critics, celebrated the news. "JUSTICE IN AMERICA!" he wrote on social media. "He has been so bad for our Country, for so long."

Trump fired Comey in 2017, early in his first term in office. He has since regularly assailed Comey's handling of the FBI investigation that detailed contacts between Russians and Trump's 2016 campaign.

Since Trump returned to office last January, his Justice Department has been examining Comey's 2020 testimony when he addressed Republican criticisms of the Russia investigation and denied that he had authorized disclosures of sensitive information to the news media.

The indictment alleges that Comey misled Congress by claiming he had not authorized anyone else to be an anonymous source in news reporting about an FBI investigation.

Trump's administration has carried out a sweeping campaign to remake the Justice Department, which the president alleges was used as a political weapon when he left office in 2021. Trump faced federal charges of mishandling classified documents and trying to overturn his 2020 election defeat. Both cases have been dropped.

"Donald Trump has ordered the criminal prosecutions of political targets, and the Department of Justice is corruptly obeying," said Norm Eisen, a prominent former government ethics official under Democratic President Barack Obama and currently a fellow at the Brookings Institution. "This indictment has all the hallmarks of a vindictive and meritless prosecution."

TENSIONS WITHIN JUSTICE DEPARTMENT

The effort to target Comey had been viewed with skepticism in the Eastern District of Virginia, the U.S. attorney's office handling the case.

After the district's top federal prosecutor, Erik Siebert, resigned last week, others in the office told his successor, Lindsey Halligan, that charges should not be filed due to a lack of evidence, according to a source.

Halligan most recently served as a White House adviser, and before that was one of Trump's personal defense lawyers.

Comey's son-in-law, Troy Edwards, resigned from his position as a senior national security prosecutor following the news on Thursday, according to a copy of his resignation letter seen by Reuters.

Comey's eldest daughter, Maureen Comey, was fired from her job as a federal prosecutor in Manhattan in July. She filed a lawsuit earlier this month, with her lawyers saying in the complaint that she was fired "solely or substantially because her father is former FBI Director James B. Comey."

Trump and Comey have had an acrimonious relationship since the start of the president's first term. Trump fired him as FBI director days after Comey publicly confirmed that the president was under investigation over his election campaign's connections to Russia. Comey then emerged as a prominent critic of the president, calling him "morally unfit" for office.

Comey's firing led to the appointment of another former FBI chief, Robert Mueller, being appointed as a special counsel to take charge of the Russia probe, which unearthed numerous contacts between the campaign and Russian officials, but concluded that there was not enough evidence to establish a criminal conspiracy.

Trump repeatedly attacked the investigation as a "witch hunt." His second administration has sought to undermine conclusions by U.S. intelligence and law enforcement agencies about Russian interference in the 2016 presidential election in which Trump defeated Democratic rival Hillary Clinton.

A Justice Department internal watchdog found evidence of numerous errors but no political bias concerning the FBI's opening of the investigation. Republicans have long claimed that the investigation was intended to undermine Trump's first administration.

The Justice Department's internal watchdog in a 2019 report faulted Comey for asking a friend to give memos detailing Comey's one-on-one interactions with Trump to the New York Times. The Justice Department during Trump's first term declined to pursue criminal charges against Comey.

(Reporting by Andrew Goudsward and Sarah N. Lynch; writing by Andy Sullivan; editing by Scott Malone, Cynthia Osterman and Leslie Adler)