Andrew J. (Andy) Biemiller, 75, the labor movement's chief congressional lobbyist for a quarter of a century and a former member of the House of Representatives, died of congestive heart failure April 3 at Suburban Hospital in Bethesda.

Mr. Biemiller, a top lieutenant of the late AFL-CIO president George Meany, played a leading role in the passage of landmark civil rights and social welfare legislation. He was regarded by observers as a formidable and effective force in the halls of Congress during the long-ago days of time-tested loyalties, lobbyist-to-lawmaker contacts and give-and-take.

AFL-CIO President Lane Kirkland and Secretary-Treasurer Thomas R. Donahue said in a statement that Mr. Biemiller was "the voice of American labor on Capitol Hill for a generation" and that "trade unionists of today and tomorrow will benefit from the pioneering legislative work he did on behalf of all Americans."

When he retired in 1978 after 22 years as director of the AFL-CIO department of legislation, Mr. Biemiller, a portly, gruff, scotch-drinking man, said, "Congress has changed a hell of a lot over the years. More and more of the people up there are concerned only about their own district and about nothing else. They don't listen to the leadership. Candidates run on their own and think about their own districts, their own reelection."

He spoke not only from the standpoint of a 25-year veteran of Capitol Hill but also as a two-term Democratic congressman from Milwaukee in the 1940s. He served in the Wisconsin legislature in the 1930s.

Mr. Biemiller once said his most satisfying lobbying achievement was his part in blocking President Nixon's nominations of Clement F. Haynsworth Jr. and G. Harold Carswell as Supreme Court justices.

He was an architect of the landmark civil rights plank that Vice President Hubert H. Humphrey, then mayor of Minneapolis, introduced at the 1948 Democratic National Convention. He was a force behind a successful campaign for inclusion of a fair employment practices clause in the 1964 civil rights bill, although this aspect of the measure had been opposed by President John F. Kennedy and Attorney General Robert F. Kennedy, according to Mr. Biemiller. Another program supported by Mr. Biemiller was comprehensive national health insurance.

Mr. Biemiller, who lived in Bethesda, was born in Sandusky, Ohio. He graduated from Cornell University in 1926. He was a professor of history at Syracuse University and the University of Pennsylvania. He became a trade union organizer while a member of Robert LaFollette's Progressive Party in Wisconsin in the 1930s.

Survivors include his wife, Hannah of Bethesda; a son, Dr. Andrew Biemiller Jr. of Toronto; a daughter, Nancy Boerup of Wooster, Ohio, and four grandchildren.