Lawyers for Baltimore City council President Walter S. Orlinsky, who is facing federal corruption charges, have asked a federal judge to dismiss the charges on grounds that federal prosecutors have targeted several key defense witnesses for indictment.

In papers filed this week at the federal courthouse in Baltimore, the lawyers said that the prosecutors' actions have placed a chill on Orlinsky's ability to prepare a defense. Potential defense witnesses who might have testified will now have to invoke their Fifth Amendment right against self-incrimination, the lawyers said.

Because of this, the motion said, Orlinsky has been denied his constitutional right to due process.

The motion by Orlinsky's lawyers, Ronald Ellison and Michal Kaminkow, did not name any of the potential witnesses. The lawyers and U.S. Attorney Frederick Motz could not be reached for comment yesterday.

Orlinsky was indicted by a grand jury last April on charges that he was given about $11,000 in exchange for promises to influence the awarding of city sludge-hauling contracts.

The grand jury alleged that the payments came from Edward Russell, a lobbyist representing three different sludge companies. Russell was working for the FBI at the time the payments were allegedly made, between December 1980 and January 1982.