A federal judge today threatened to hold Justice Department officials in contempt if they continue their sharp criticism of his conduct in the case of a Selective Service law violator.

U.S. District Court Judge Terry J. Hatter Jr., clearly angered by a government refusal to provide confidential documents, called language in a Monday response from the government "uncalled for" and said "a contempt hearing will be held after this proceeding" if it recurred.

Hatter has become a potentially key stumbling block to further government prosecution of about 500,000 men who have failed to register with Selective Service. Unlike a handful of other judges who have handled cases of resistance to the new law, Hatter has given a preliminary ruling that the government has illegally discriminated by indicting only those violators who publicly announced their resistance to the law.

Hatter has ordered that presidential counselor Edwin Meese III testify on his role in forming government policy to encourage men to fill out registration cards, and demanded that the government show him large portions of government documents already submitted that are censored.

In the Monday response, the U.S. attorney's office here said "it is clear that the court's appetite for more and more irrelevant disclosure of sensitive material has become insatiable . . . . It is also apparent with each new disclosure made pursuant to near impossible deadlines, the court feels compelled to impugn the motives of the government."

Officials in the U.S. attorney's office said today that the objectionable language had been dictated by officials in Washington and that they had objected and would seek the court's permission to submit a modified response.

Hatter indicated that as a former assistant U.S. attorney in California he suspected that the language had come from Washington. Mark Rosenbaum, one of the attorneys representing Selective Service resister David Wayte of Pasadena, said after the hearing that he thought the language "was written by Attila the Hun."

Hatter today agreed to Assistant U.S. Attorney Robert Romero's request for a day's delay so that Washington officials could decide whether to appeal the judge's order to produce Meese and the uncensored documents. Hatter has asked the government to prove why he should not dismiss the case on the grounds that young men who have avoided registering without announcing their acts publicly have not been indicted.

Romero said earlier that the government was going to begin "active" enforcement of the law, but Hatter referred today to a defense document indicating that all 13 men indicted so far had publicly identified themselves as resisters prior to their indictments.

Hatter mentioned twice his chagrin at the government's being so reluctant to provide him with documents that it had not even honored a request for a copy of a Washington Post article that quoted one government official as saying that prosecutions of resisters ought to be confined to small, military-oriented communities.