US Representative John F. Tierney’s brother-in-law is asking a federal judge to sentence him to no more than a year and a day in prison on Thursday for taking part in an illegal sports betting operation that also ensnared the congressman’s wife.

In a brief filed on Monday, a lawyer for Daniel Eremian, 62, of Boca Raton, Fla., said the requested term, which is about three years less than what prosecutors seek, is appropriate, in part because Eremian was not a leader of the gambling ring.

His lawyer, Marc S. Nurik of Fort Lauderdale, Fla., also wrote that Eremian did not use violence to collect gambling debts, pressured none of the wealthy bettors to place wagers, and was treated more harshly than coconspirators with immunity deals, even though most of them were “more criminally involved.”

Eremian and a codefendant, Todd Lyons, 38, of Beverly, were convicted in December in federal court in Boston for their roles in Sports Offshore, the Antigua-based sports betting website launched by Eremian’s brother, Robert, and others.

Robert Eremian was also charged in connection with the case but remains a fugitive.

The Eremians’ sister — Tierney’s wife, Patrice — pleaded guilty in 2010 to helping Robert Eremian falsify tax filings and was sentenced to a month in prison and five months of house arrest.

Congressman Tierney, a Salem Democrat, was never charged in connection with the operation and has denied any knowledge of it.

In letters to the sentencing judge made public on Monday, relatives and a friend of Daniel Eremian, retired Peabody police Lieutenant John C. Tivey, described him as a devoted family man.

“It has been very stressful on all of us but we’ve held together as a family and are preparing for the worst and hoping for the best,” wrote Daniel Eremian’s wife, Rhonda.