WASHINGTON (AP)  The Justice Department on Wednesday recommended a reduction in jail time for the disgraced lobbyist Jack Abramoff, who became a crucial witness against lawmakers and Congressional aides.

Prosecutors asked federal judges in Washington and Florida to shave years off the sentence of Mr. Abramoff, citing his work in an investigation by the Federal Bureau of Investigation that sent numerous people to prison and contributed to the Republican Party’s loss of Congress.

Mr. Abramoff’s cooperation helped send to prison former Representative Bob Ney, a Republican, and former Deputy Interior Secretary J. Steven Griles.

In 2006, Mr. Abramoff began serving almost six years in prison for a fraudulent Florida casino deal. In addition, he faces about 11 years in prison when he is sentenced Sept. 4 for corrupting Capitol Hill lawmakers.