Chicago ? Facing almost certain defeat in a Senate impeachment trial, Gov. Rod Blagojevich might ask the courts to step in and block a proceeding that he considers “a sham,” a lawyer for the Democratic governor said Thursday.

Attorney Samuel E. Adam said Thursday that a lawsuit challenging what he called “completely unfair” Senate trial rules is being prepared and could be filed to the state Supreme Court within days, pending a final decision on whether to move forward.

Blagojevich’s trial is set to begin Monday. The governor said he has no intention of mounting a defense unless rules are changed before the Senate trial that will determine whether he’s thrown out of office.