A Senate Appropriations subcommittee has postponed Attorney General Alberto R. Gonzales’ scheduled April 12 appearance to testify about the Justice Department’s budget.

Gonzales’ testimony before the Commerce, Justice and Science Appropriations Subcommittee was to have been his first appearance before a congressional panel in nearly three months. In the interim, a widening probe over his role in the firing of eight U.S. attorneys has prompted calls for his resignation.

“I believe it would be very difficult in this environment to give the department’s budget request the attention it deserves until the Senate has examined the department’s leadership failures,” Barbara A. Mikulski, D-Md., the Commerce-Justice-Science Subcommittee chairwoman, said in a statement released Thursday.

The postponement ensures Gonzales’ appearance will not overshadow his scheduled April 17 testimony before the Senate Judiciary Committee regarding the firings.

Also on Thursday, Judiciary Chairman Patrick J. Leahy, D-Vt., sent Gonzales a letter asking him to “include in your written testimony a full and complete account of the development of the plan to replace United States attorneys, and all the specifics of your role in connection with that matter.”

Gonzales faced new complications last week, as his former chief of staff contradicted statements the attorney general had made about his role in the firing of eight U.S. attorneys.

“I don’t think the attorney general’s [March 13] statement that he was not involved in any discussions about U.S. attorney removals is accurate,” Kyle Sampson told the Senate Judiciary Committee March 29.