GREENSBORO, N.C. -- The judge overseeing John Edwards' criminal trial has canceled a hearing on whether to quash a subpoena issued to a former speech writer for the two-time presidential candidate.

The hearing was scheduled for Friday.

Edwards' lawyers are seeking an extensive list of documents from Wendy Button, a 2008 campaign staffer expected to testify.

U.S. District Court Judge Catherine C. Eagles said Wednesday another judge would have to decide the issue because her husband is a former law partner of one of the lawyers representing Button, presenting a potential conflict.

In court documents filed Thursday, Eagles reversed course, canceling Friday's hearing and ordering the lawyers involved in the issue to file written briefs with the court.

Opening statements in Edwards' trial over campaign finance violations are scheduled for Monday.