Republican Congressman Duncan Hunter submitted his formal letter of resignation to House Speaker Nancy Pelosi and California Governor Gavin Newsom on Tuesday, a month after he pleaded guilty to conspiring to steal campaign funds in federal court. Hunter vowed to resign "shortly after the holidays" in early December.

In his letter to Pelosi and Newsom, the California congressman highlighted his military service before entering Congress and his accomplishments in the House, saying he was proud of "giving a voice to our men and women in uniform" as a member of the Armed Services Committee.

Hunter reversed his previous not guilty plea in federal court in San Diego on December 3, after spending months decrying and denying the allegations against him. He was then was informed by the Ethics Committee that House rules bar someone from voting when he or she is convicted of a crime that could incur a sentence of two or more years.

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Hunter admitted that he knowingly and willfully took hundreds of thousands of dollars in campaign cash so that he and his wife, Margaret, could maintain their lifestyle. Margaret Hunter pleaded guilty in June.

The plea agreement said the Hunters used more than $150,000 in campaign funds to pay for everything from fast food meals and movie outings to luxury vacations and plane tickets for their pet rabbits. The congressman also used more than $1,000 in campaign funds to pay for a ski trip on 2010 with someone prosecutors described as "one of his girlfriends."

Hunter, 42, faces up to five years behind bars when he's sentenced in March, but federal prosecutors are pushing for a little over a year. The charge also comes with a fine of up to $250,000.

Hunter insisted for months that he was the target of a political "witch hunt," insisting the allegations lacked merit.