FILE PHOTO: Former FBI Director James Comey testifies before a Senate Intelligence Committee hearing on Russia's alleged interference in the 2016 U.S. presidential election on Capitol Hill in Washington, U.S., June 8, 2017. REUTERS/Aaron P. Bernstein/File Photo

By Sarah N. Lynch and Andrew Goudsward

WASHINGTON (Reuters) -A federal judge on Monday dismissed criminal charges against two perceived adversaries of President Donald Trump -- FBI Director James Comey and New York Attorney General Letitia James -- ruling that the U.S. attorney he hand picked to prosecute them was unlawfully appointed.

The ruling throws out two cases Trump had publicly called for as he pressured Justice Department leaders to move against high-profile figures who had criticized him and led investigations into his conduct.

Lindsey Halligan, a former personal lawyer to Trump, was named interim U.S. Attorney for the Eastern District of Virginia in September to take over both investigations despite having no previous prosecutorial experience.

The findings by U.S. District Judge Cameron McGown Currie come after both Comey and James accused the Trump Justice Department of violating the U.S. Constitution's Appointments Clause and federal law by appointing Halligan in September.

'NO LEGAL AUTHORITY'

Currie found that Halligan "had no legal authority" to bring indictments against either Comey or James. But Currie dismissed the cases "without prejudice," giving the Justice Department an opportunity to refile the cases with a different prosecutor at the helm.

"All actions flowing from Ms. Halligan’s defective appointment," Currie wrote, were "unlawful exercises of executive power and are hereby set aside."

“I am heartened by today’s victory and grateful for the prayers and support I have received from around the country," James said in a statement. Her attorney, Abbe Lowell, said James would "continue to challenge any further politically motivated charges through every lawful means available.”

A lawyer for Comey and a spokesperson for the Justice Department did not immediately respond to requests for comment.

Trump ordered Attorney General Pam Bondi to install Halligan to the post after her predecessor Erik Siebert declined to pursue charges against Comey or James, citing a lack of credible evidence in both cases.

HALLIGAN MOVED SWIFTLY

Shortly after her appointment, Halligan alone secured indictments against Comey and James after other career prosecutors in the office refused to participate.

Comey has pleaded not guilty to charges of making false statements and obstructing Congress. James has pleaded not guilty to charges of bank fraud and lying to a financial institution.

Attorneys for Comey and James argued that Halligan's appointment violated a federal law they said limits the appointment of an interim U.S. attorney to one 120-day stint.

Repeated interim appointments would bypass the U.S. Senate confirmation process and let a prosecutor serve indefinitely, they said. Siebert previously had been appointed by Bondi for 120 days and was then re-appointed by the U.S. District Court for the Eastern District of Virginia, since the Senate had not yet confirmed him in the role.

Lawyers for the Justice Department argued the law allows the attorney general to make multiple interim appointments of U.S. Attorneys. Still, Bondi sought to shore up the cases by separately installing Halligan as a special attorney assigned to both prosecutions. In that same document, she also said she ratified the indictments.

The challenge to Halligan's appointment was one of several efforts lawyers for Comey and James have made to have the cases against them thrown out before trials. Both also argued that the cases are "vindictive" prosecutions motivated by Trump's animosity.

At a hearing on November 13, Currie repeatedly raised doubts about why the Justice Department felt it was necessary to take that step if it believed Halligan's appointment was lawful.

(Reporting by Andrew Goudsward; editing by Scott Malone, Bill Berkrot and Alistair Bell)