WASHINGTON, D.C. -- The last remaining U.S. independent counsel, David Barrett, after spending $21 million over 10 years, on Jan. 12 finally will close down his investigation of former Housing Secretary Henry Cisneros' lying to FBI investigators about hush money paid to an ex-mistress. The political significance is that the Barrett report's shocking allegations of high-level corruption in the Internal Revenue Service and Justice Department are likely to be concealed from the public and from Congress.

 A recently passed appropriations bill, intended to permit release of this report, was altered behind closed doors to ensure that its politically combustible elements never saw the light of day. But if that happens, Republican Sen. Charles Grassley will still try to force its release. As chairman of the Senate Finance Committee with oversight of the IRS, he wants the first real investigation of the tax agency.

 That investigation would be a long walk into the unknown, with possibly far-reaching consequences. Prominent Democrats in Congress have spent much of the last decade in a campaign, successful so far, to suppress Barrett's report. Its disclosures could dig deeply into concealed scandals of the Clinton administration. These vital considerations, not the mere continuation of a $58-an-hour independent counsel position, is why Republican lawyer Barrett for a decade would not close down his prosecutor's office.

 If this were just about one politician's illicit love life ruining his political career, Barrett would have ended his operation long ago. But an IRS whistle-blower told Barrett of an unprecedented cover-up. The informant said a regional IRS official had formulated a new rule enabling him to transfer an investigation of Cisneros to Washington to be buried by the Justice Department. Barrett's investigators found Lee Radek, head of Justice's public integrity office, determined to protect President Bill Clinton.

 That triggered intensive efforts to get rid of Barrett and suppress his report by three of the toughest Democrats in Congress: Sen. Carl Levin, Sen. Byron Dorgan and Rep. Henry Waxman. At the same time, the powerhouse Washington law firm of Williams & Connolly -- representing not only Cisneros but also the Clintons -- was filing multiple suits with federal appellate judges supervising the independent counsel.

 The sympathetic judges sealed everything concerned with the case, including the report. Barrett was instructed to remain deathly silent on pain of criminal prosecution. Yet Levin, as ranking Democrat of a Senate oversight committee, eight years ago gained access to the raw data of Barrett's prosecutorial effort after requesting it in a Nov. 20, 1997, letter to the judges.

 Barrett's densely packed 120-page report is followed by a 500-page appendix with more than 2,500 footnotes. Grassley thought he had an agreement with Dorgan to amend the Treasury appropriations bill to close down Barrett's office and publicly release "all portions of the final report" except for any "clearly unwarranted invasion of privacy."

 But Grassley is not an appropriator, and Democrats in the Senate-House appropriations conference slipped through a critical change. The final language authorized the judges "to protect the rights of any individual named" in the report. With two out of three judges on a three-judge panel inclined to the Democrats, that means hardly any of Barrett's allegations will remain in the report made public. The bill was passed by Congress on Nov. 18 and signed into law Nov. 30.

 Republican congressional sources expect Section B of the report, dealing with the allegations of IRS-Justice corruption, to be eliminated in its entirety. The rest of the report will be so heavily redacted to obey the new congressional language that it will be of scant interest to either ordinary citizen or legislator. This long, tendentious battle to keep David Barrett away from opening a probe into what really happened in the Clinton administration then will have appeared to have been concluded with an unconditional victory.

 But maybe not. Chuck Grassley is a stubborn Iowa farmer who often drives the White House and Republican leaders to distraction. He has said that if the Barrett report finally emerges as a mutilated remnant in order to protect the IRS, he will press for legislation to change that. It may be the last hope for the truth to emerge.