The House Democratic leadership has abruptly postponed floor consideration of legislation extending the independent counsel law, an action apparently prompted by fears that the House might approve an amendment subjecting members of Congress to the law.

The House had been scheduled to take up the legislation yesterday, but uncertainty over the fate of the amendment offered by Rep. E. Clay Shaw Jr. (R-Fla.) led to a sudden reshuffling of the House calendar.

Asked about the change yesterday at his regular news conference, House Speaker Jim Wright (D-Tex.) said the schedule had been altered to permit the House to take up legislation authorizing funding for airport improvements.

But the House seemed in little hurry to take up the airport bill, since it delayed its scheduled 10 a.m. opening until 2 p.m. and did not plan to complete action on that legislation until today.

Shaw said the postponement was due to "growing concern over my amendment -- there's no question that's the reason."

Rep. Newt Gingrich (R-Ga.) dismissed the speaker's explanation as "baloney," and said the real reason was "they thought it {the Shaw amendment} would pass."

House Democrats, added Gingrich, "are feeling a little antsy right now" because of a spate of ethics cases and allegations of improprieties involving members of the majority party. Gingrich and some outspoken GOP colleagues have engaged in a sporadic campaign to highlight what they call a "pattern" of corruption among House Democrats.

Adding to the Democrats' discomfort, said the Georgia Republican, was an "unseemly story" in The Washington Post last week describing how Wright has received unusually high royalties from the sale of a book he wrote that was published by a longtime friend.

The article reported that Wright had received almsot $55,000 in royalties from the sale of the book, "Reflections of a Public Man," at a rate nearly five times the standard royalty percentage for authors. The friend who published the book owns a printing company that was paid $265,000 for performing campaign services for the speaker last year.

House leaders said they would reschedule a vote on the independent counsel extension as early as next week.

The independent counsel law, enacted as part of the 1978 Ethics in Government Act, is scheduled to expire on Jan. 2, 1988. The law is designed to prevent conflicts of interest affecting the Justice Department in criminal probes involving senior officials of the executive branch.

Under the law, the Justice Department is required to conduct preliminary investigations in cases where allegations are brought against senior government officials. If Justice finds that further investigation is warranted, an independent counsel is appointed by a three-judge panel of the U.S. Appeals Court for the District of Columbia.

Shaw's amendment would make members of Congress also subject to mandatory independent counsel investigations.

House Majority Leader Thomas S. Foley (D-Wash.) said yesterday the Shaw amendment "doesn't make any sense" because the "whole purpose of the law is to insulate conflicts of interest in the executive branch."

House Majority Whip Tony Coelho (D-Calif.) called the drive to include members of Congress "purely a political ploy" designed to embarrass Democrats. Republicans who want to see criminal complaints brought against members of Congress, Coelho said, "have the right to go to {Attorney General} Ed Meese and he can investigate any action he wants."