Attorney Michael A. Young’s refusal to submit to a government security clearance procedure may end in his removal as defender for one of the men accused of conspiring with Usama Bin Laden to commit acts of terrorism against the United States.

In a hearing interrupted when one of several alleged terrorists tried to attack U.S. District Judge Leonard B. Sand, Mr. Young said yesterday that requiring a security clearance to see classified documents in the case is burdensome, intrusive, and impinges on the attorney-client relationship and attorney work product. He also said it tips the scales of the adversary system in favor of the prosecution.