A federal judge here blocked implementation of a new Army civilian drug-testing program, scheduled to being yesterday, that requires random tests of all employes "critical" to internal or national security.

Yesterday's action by U.S. District Court Judge Thomas F. Hogan came the morning after he ruled that he did not have jurisdiction to decide the challenge to the new program brought by the National Federation of Federal Employes and its local, which represents about 200 security guards at Aberdeen Proving Ground, Md., who are included in the program.

In a Monday night ruling in which he denied the union's request for a preliminary injunction, Hogan said the program raises serious constitutional questions concerning privacy and protections against unreasonable search afforded by the Fourth Amendment, but that the matter is basically a labor-management dispute.

Under the Civil Service Reform Act, he said, the Federal Labor Relations Authority and the Merit Systems Protection Board have jurisdiction.

But yesterday morning, Hogan stayed his order and issued an injunction blocking the drug-testing program pending a decision by the U.S. Court of Appeals on the union's request for an expedited appeal.

Red Evans, a spokesman for the union, said the union filed notice of appeal yesterday.

The drug-testing program, affecting 10,000 to 12,000 civilian Army employes ranging from security guards to those who work in nuclear facilities, was to be implemented in two parts. The first required all current "critical" employes and applicants for those posts to sign a urinalysis consent form as a condition of employment.

Random drug-testing was to have begun yesterday at Aberdeen and the program was to be in effect nationwide by the middle of next month.

The union had argued that under the jurisdiction of the FLRA and the MSPB, the drug program might never receive "adequate judicial review," partly because the Army argues that the matter is not negotiable by the union.

Government attorneys could not be reached for comment.