CHICAGO (AP) -- Ousted Gov. Rod Blagojevich's attorneys are asking a federal judge to postpone his corruption trial, saying they can't be ready by the scheduled June 3 start date.

The attorneys said in a six-page brief filed Thursday with U.S. District Judge James B. Zagel that it would be physically impossible to wade through the massive amount of paperwork necessary to be ready for trial on time.

They also cited the possibility that the U.S. Supreme Court might find some of the charges in the indictment unconstitutional. The high court is considering related cases now.

A spokesman for the U.S. attorney's office had no comment.