Lawyers for the U.S. Justice Department said in a court filing Wednesday that Arpaio repeatedly boasted about his immigration enforcement efforts when he thought it was in his best interest.

Arpaio is arguing that allowing such statements at trial would have a chilling effect on protected political speech.

Arpaio is scheduled to be tried April 25 on a criminal contempt of court charge for ignoring a 2011 court order in a racial profiling case to stop his patrols.

Arpaio, who could face up to six months in jail if convicted, has acknowledged prolonging the patrols, but insists he did so unintentionally.

An Arpaio attorney said in a court filing late last week that it would be prejudicial to use Arpaio's comments during campaigns at his trial and that the remarks were campaign posturing and not made under oath.