HELENA, Mont. (AP) — U.S. Sen. John Walsh of Montana says he is dropping his campaign for office amid allegations that he plagiarized large portions of a 2007 research project he wrote for a master’s degree.

In a statement to supporters, the Democrat and former National Guard commander said he is leaving the race but will keep the seat he was appointed to until his term ends in January 2015.

The announcement comes as a U.S. Army War College investigation is set to begin Aug. 15 into the paper Walsh wrote. He has said the copying was unintentional.

Walsh’s decision is likely to give a boost to Republican Rep. Steve Daines, who is giving up his House seat to run for Senate.

The Montana Democratic Party must hold a nominating convention to choose a replacement candidate before an Aug. 20 deadline.

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