Last week, Rep. Herbert E. Harris (D-Va.) had the Department of Housing and Urban Development on the defensive with a much-trumpeted announcement that he had uncovered a multi-million dollar "slush fund" in the department's low-income housing programs.

Yesterday it was HUD's turn. Housing Secretary Moon Landrieu and others went to Capitol Hill to denounce the Northern Virginia Democrat for exaggerating the findings of a General Accounting Office investigation.

Landrieu, appearing before Harris's Post Office and Civil Service Committee angrily told the congressman that his charges "are utterly and totally baseless and untrue. There is no slush. There is no fund."

Waving scrapbook of newspaper clippings about Harris' charges, Landrieu accused Harris of using the media "to create the impression in the public mind that a scandal in the federal government has been uncovered."

Jerome H. Stolarow of the GAO joined Landrieu in defending HUD of wrongdoing. "The money is not being improperly used in any way," Stollarow said. "There is no evidence of a slush fund."

Rep. Edward P. Boland (D-Mass.), chairman of the House appropriations subcommittee that considers HUD's budget, told Harris in a letter that the GAO had uncovered "a very technical accounting problem" that should not be "exaggerated to the point that it could damage badly needed federal housing assistance for low- and moderate-income people."

The feisty Harris refused to concede that he had overplayed the findings of the report. In answer to a charge by Landrieu that Harris was "being judge, jury and prosecutor," Harris accused the cabinet officer of trying to "come up here and fight and not reveal."

Harris insisted that the investigations had shown that HUD, deceived Congress by obligating money to housing projects it had no intention of approving. The unspent money, Harris charged, was available in the next fiscal year "at HUD's discretion without the knowledge or approval of Congress."

Proof of his charges, Harris said, was Landrieu's agreement to "revise out (accounting) procedures" to conform to GAO standards.