The House District of Columbia Committee voted 6 to 5 yesterday to approve a bill that would grant the District statehood and full representation in Congress, touching off a brief celebration by supporters and setting the stage for what could be a much tougher fight on the House floor this fall.

The committee's action, following more than a month of political skirmishes and debate over the measure's constitutionality, was hailed by committee Chairman Ronald V. Dellums (D-Calif.) as an "historic" moment in the fight to fully enfranchise the District's nearly 630,000 residents.

"There should be no colonies in a democracy, and the District of Columbia continues to be a colony," Dellums said.

Del. Walter E. Fauntroy (D-D.C.), chief author of the bill, announced that 90 other House members have cosponsored the bill and said he would wage a nationwide campaign, tied to the bicentennial celebration of the Constitution, to pressure the House to approve the bill by mid-September. Fauntroy had predicted earlier that the bill would reach the House floor before the July 4 recess.

The bill would grant the State of New Columbia full representation in the House and Senate, budget autonomy and an independent judiciary and prosecutorial system. It also would replace the mayor and D.C. Council with a governor and a state legislature. The District currently operates under a home rule charter and is represented by a lone nonvoting delegate in the House.

The Democrats, who hold a 7-to-4 majority on the committee, fended off most of the amendments introduced by Republicans, including ones to eliminate the federal payment to the District, force the closing of the District-run Lorton Reformatory in Fairfax County, and replace a statehood constitution recently approved by the council with a far more controversial document approved by District voters in 1982.

Rep. Romano L. Mazzoli (D-Ky.), who argued that Fauntroy and the council were wrong to have scrapped the constitution approved by voters, sided with the Republicans on most key issues and joined with them in voting against the overall bill.

Fauntroy, who had counted on Mazzoli's support earlier this year despite his reservations, said yesterday he was disappointed and baffled by Mazzoli's vote.

"I felt the {constitutional} questions that he raised initially were valid questions, but the answers that we gave were more than sufficient to answer those questions," Fauntroy said.

"In the past, Mr. Mazzoli was very cogent and clear in stating his concerns. But in this particular debate, I found that that cogency and clarity deserted him."

Mazzoli refused to comment after the committee meeting.

Those voting for the bill were Reps. Fortney H. Stark (D-Calif.), William H. Gray III (D-Pa.), Mervyn M. Dymally (D-Calif.), Alan Wheat (D-Mo.), Dellums and Fauntroy. Opponents were Reps. Thomas J. Bliley Jr. (R-Va.), Larry Combest (R-Tex.), Lynn M. Martin (R-Ill.), Stan Parris (R-Va.) and Mazzoli.

House Speaker Jim Wright (D-Tex.) and Majority Leader Thomas S. Foley (D-Wash.) have endorsed the statehood drive, and the list of cosponsors includes Rep. Les Aspin (D-Wis.), chairman of the Armed Services Committee; Rep. David E. Bonior (D-Mich.), a member of the House leadership, and Rep. Peter W. Rodino Jr. (D-N.J.), chairman of the Judiciary Committee.

Proponents of the bill have said they need to win by a wide margin in the overwhelmingly Democratic House to improve their chances of winning passage in the Senate, where the Democrats hold a slender majority. Mazzoli's defection could damage the effort, according to some observers. Neither Fauntroy nor Dellums would speculate yesterday on how well the bill would do on the House floor.

"I don't know where the House is on this matter," Dellums said. "We've got to start the spade work."

Parris said that even if the bill survives tests in the House and the Senate, "I'm sure the White House and the president will have grave concerns about the bill." Assistant U.S. Attorney General Stephen J. Markham testified in April that the administration "vigorously opposes" statehood because the proposal "is simply inconsistent with the federal system as it has existed for the past 200 years."