Updated

Talk about hardball politics.

Rep. John Murtha's opponent in the 2008 election claims the Pennsylvania congressman's chief of staff has threatened to have him recalled to active duty and court-martialed for campaigning while in the military, which is in violation of military code.

Bill Russell, an Iraq war veteran who served with the Army, told FOXNews.com that Murtha's chief of staff, John Hugya, made the threat on two occasions -- first to his former commanding officer and then to his face in March.

"It's a terrible, terrible threat to make," said Russell, a Republican who lost to the Democratic powerhouse in November but plans to challenge him again in 2010. Asked if Murtha is trying to bully him out of a rematch, Russell said: "It was a direct intent to intimidate."

Russell was on active duty for a three-month period -- from April to July -- of his campaign for Congress last year. But he said he did not campaign during that period, as Hugya was suggesting, and so did not violate military code that prohibits doing so.

"I'm very comfortable with the fact that I didn't do anything wrong and there's nothing to court martial me for if they try to do it," he said. But he said Murtha's reputation as a powerbroker on Capitol Hill puts him on edge.

"When you have a threat to be made so brazenly and openly ... you've got to take it seriously," he said.

Murtha spokesman Matthew Mazonkey wrote in an e-mail that his boss is "absolutely not" trying to intimidate Russell to get him out of the race.

"We take every challenge seriously, even challenges from people who have already been defeated by double-digits," he said, referencing Murtha's 16-point margin of victory last year.

But Murtha's office did not deny Russell's charge. Instead, the congressman and Russell offered conflicting accounts of the most recent encounter, in which Hugya broached the topic of Russell's active-duty stint at an NRA dinner in March.

Russell, who described the encounter as hostile, said he was working the tables at the event when Hugya threatened him, saying: "What are you gonna do when we have the new secretary of the Army seated and have your ass recalled to active duty for that s--- you pulled last summer?"

Mazonkey, who described the conversation as informative, wrote in an e-mail to FOXNews.com that Hugya, "who is a retired Marine Colonel, was reminding Mr. Russell that his conduct while in uniform during the last campaign was in violation of sections of the uniform code of military justice."

He wrote that Russell was "sending out campaign literature with a picture of himself in uniform and listing himself as Lt. Col. William Russell," in violation of military code during his active-duty period.

He did not say whether Murtha's office intends to pursue a court-martial.

While Hugya did not explicitly threaten to bring Russell up on charges during the March conversation, he apparently did in a conversation in January with Ret. Col. Gregory Ritch, who served as Russell's commanding officer.

Ritch said he was talking on the phone with Hugya about an unrelated topic when Murtha's chief of staff suddenly switched topics to Russell, whom he referred to as the "carpetbagger."

According to Ritch, Hugya said: "He's gonna get a big surprise here shortly when the new secretary of Army calls his ass back for active duty."

Ritch said he asked why, and Hugya told him Russell would be court-martialed.

Ritch noted that he and Hugya have a standing relationship, and so he "didn't take it very seriously" when Hugya made the threat. That's just how he talks, Ritch explained.

"I thought he was just blowing off steam," he said, though he notified a military judge of the conversation at the time.

But when Ritch heard from Russell about the similar exchange in March, he said it raised alarms.

In retrospect, Ritch said, Hugya may have been trying to solicit his consent or cooperation in a court-martial. But he said Russell did nothing wrong and a court-martial would be a mistake.

"Lt. Col. Russell is an outstanding soldier. He's a credit to this great nation ... And I would just hope that Mr. Hugya would not consider, or Congressman Murtha even consider, something of this magnitude."

Russell also notified donors of the alleged threats in a fundraising letter.