ATTORNEY GENERAL William French Smith is not likely to spend the remaining weeks of his term serving a jail sentence for contempt of Congress. Sen. Charles Grassley (R-Iowa) brought such a charge against Mr. Smith last week, but the circumstances under which the citation was issued are unusual, and support for the action from Senate colleagues uncertain.

What is behind this is a dispute between a pair of Senate subcommittees and the Justice Department over documents involving three defense contractors: Lockheed, the Newport News Drydock and Shipbuilding Co. and the Electric Boat Division of General Dynamics. In August Sens. Grassley and William Proxmire (D-Wis.), chairman and vice chairman, respectively, of the two subcommittees, wrote to the department asking for files concerning alleged wrongdoing by these companies in carrying out Navy contracts for shipbuilding. The contracts go back almost 15 years, and investigations were begun during the Carter administration. The Lockheed investigation was closed in 1979, General Dynamics in 1981 and Newport News in 1983.

Why the sudden interest in these cases? New allegations by a former General Dynamics vice president concerning bids on ships contracts have caused the department to reopen the case involving that company, and have sparked interest on the Hill in earlier decision not to bring criminal prosecutions. While the Justice Department has produced material subpoenaed by the subcommittees about the Lockheed and Newport News cases, it is understandably reluctant to provides files on the General Dynamics case, which is now the subject of a new investigation that may lead to a grand jury indictments.

Sen. Grassley could not persuade the chairman of his own committee to hold a meeting so that the contempt citation could be issued. He then used Sen. Proximer's subcommittee as a forum for issuing his charge. The citation is not valid until it is approved by the Judiciary Committee and the full Senate, events that most observers consider unlikely. Perhaps the senator has chosen this approach to focus attention on the General Dynamics case and to put public pressure on the department. If so, he has succeeded.

But conflicts about the rights and responsibilities of the various branches of Congress are not new. They arise regularly, usually when a congressional committee wants information that the executive believes is privileged, and they are particularly delicate when criminal prosecutions are at stake. Experience shows that these disagreements are almost always resolved by compromise and seldom by contempt proceedings. There is every reason to assume that after the election and the congressional recess, this dispute will be too.