The prison sentence of a Washington, D.C., political consultant who testified against a Bangor man in a phone-jamming trial last year has been reduced from five months to three.

In Concord, N.H., U.S. District Judge Joseph A. DiClerico Jr. on Thursday reduced the prison sentence of Allen Raymond, 37, of Maryland after prosecutors argued that his testimony had been crucial in obtaining a conviction against James Tobin, a Windham native and well-known Republican political consultant.

Tobin, 45, was convicted in December after a six-day jury trial of taking part in a phone-jamming scheme to keep voters from getting to the polls more than three years ago.

Raymond told the jury that he talked to Tobin a couple of weeks before the election about a plan to disrupt New Hampshire Democrats’ phone lines offering rides to the polls on Nov. 5, 2002.

Raymond is to begin serving his sentence March 2.

Tobin’s sentencing, set for March 21 before U.S. District Judge Steven McAuliffe, has been delayed until May because of his attorney’s scheduling conflicts.

Tobin faces up to five years in federal prison and a fine of up to $250,000. Prosecutors have admitted that under federal sentencing guidelines he faces “nowhere near” the maximum sentence.

Charles “Chuck” McGee, the former executive director of the New Hampshire Republican Party, and Raymond pleaded guilty a year ago to one count each of conspiracy in the phone-jamming operation.

McGee, who now lives in Manchester, N.H., was released shortly before Thanksgiving after serving seven months in a maximum-security prison in Brooklyn, N.Y. His sentence included a $2,000 fine and 200 hours of community service.

Both men testified against Tobin, but gave conflicting stories of what they knew about the plan and when it was hatched.