The Justice Department told a House subcommittee yesterday that the Reagan administration was trying to resolve, and not provoke, a dispute over the constitutionality of a section of a 1984 contracting law when it ordered agencies to ignore the bid protest provision.

Acting Deputy Attorney General D. Lowell Jensen testified that the Justice Department took the approach it did because it doubts that "anyone would have the standing to challenge the constitutionality of the provisions."

From the administration's point of view, Congress violated the doctrine of separation of powers last year when it authorized the General Accounting Office and comptroller general to delay the award of an agency contract if a legitimate protest is filed by a competing bidder.

The administration insists that the comptroller general is an officer of the legislative branch and is not allowed, under the Supreme Court's decision nullifying the legislative veto, to rule on executive branch decisions such as contract awards. Thus, based on a Justice Department opinion, the Office of Management and Budget in December ordered federal agencies to ignore the bid protest provision.

Rep. Jack Brooks (D-Tex.), who chairs the House Government Operations subcommittee on legislation and national security, has taken the opposite position -- contending that the administration has violated the Constitution by usurping the judicial branch's right to rule on the constitutionality of the law.

Lear Siegler Inc., a defense contractor, has filed suit against the Navy in federal court in California, charging that the administration has violated the Constitution by failing to enforce the bid protest provision.

The company wants to delay the awarding of a contract for fuel tanks for the F18 fighter-bomber, saying that the Navy miscalculated the currency conversion rate under the Buy America Act when it awarded the contract to an Israeli firm.

Steven R. Ross, general counsel to the clerk of the House, told the subcommittee that congressional leaders from both parties have agreed to file briefs in the case, supporting the position of Congress. Ross said that OMB's action "flatly violates the express instructions of the Constitution that the president shall 'take care that the laws be faithfully executed.' "

The Justice Department testimony yesterday set off an unusually testy debate between Jensen and the subcommittee's Republican members, with Rep. Frank Horton (R-N.Y.) challenging Jensen to produce a legal precedent to support the administration's action.

"By what authority does the attorney general have the right to declare a portion of an act unconstitutional and directly order federal agencies not to follow the law?" Horton asked. When Jensen sought to produce some examples, Horton interrupted: "I'm not playing 'what-if.' What are the facts? Has this ever been done before?"

Added Brooks: "Let's have fact, not fantasy."

"What I want to know is whether this is an innovation; whether you are breaking new ground as I think you are," Horton said. Jensen said he "thought" he had repeatedly cited the precedents, but would try to clarify his answer in writing.

Earlier OMB Director David A. Stockman used the occasion to make a case for one of President Reagan's pet proposals, the line-item veto. Stockman told the subcommittee the issue never would have arisen if the president had that power, because he would have vetoed that provision of the Deficit Reduction Act.

After Stockman left, Brooks said the OMB director was, in effect, acknowledging that the president does not now have authority to refuse to comply with "a section of a law.