NEW YORK (AP) _ A judge decides Tuesday whether Leona Helmsley, the billionaire hotel queen, must exchange her designer clothes and country estate for prison garb and a cell.

Mrs. Helmsley, the notoriously picky and sharp-tongued executive, is to be sentenced in Manhattan's federal court, where she was convicted Aug. 30 at a highly publicized trial of evading $1.2 million in federal taxes.

The 69-year-old Mrs. Helmsley could receive up to 127 years in prison if U.S. District Judge John M. Walker Jr. were to impose consecutive, maximum sentences for each of 33 counts.

The judge could give lesser time or spare Mrs. Helmsley from prison altogether by sentencing her to probation or community service. She also faces more than $7 million in fines.

Even if Walker imposes a prison sentence, Mrs. Helmsley will likely remain free while she appeals her conviction.

Her attorney, Gerald Feffer, would not discuss the sentencing.

The last obstacle to her sentencing was lifted last Monday when Walker ruled that prosecutors did not use tainted evidence against Mrs. Helmsley at the trial. Her lawyers had asked that her conviction be set aside claiming evidence used against her was obtained during 1985 grand jury investigations at which she had been granted immunity to testify.

At the time, the state was investigating possible sales tax evasion by jewelers, furriers and other retailers.

''The court is satisfied that the government's evidence used in the federal grand jury and at trial was derived from sources independent of Mrs. Helmsley's immunized testimony on unrelated matters,'' Walker said in a written decision.

Mrs. Helmsley has avoided personal publicity since the daily scrutiny of the two-month trial. She has, however, continued to be featured as a regal perfectionist in advertisements for her hotels.

Mrs. Helmsley and her 80-year-old husband, Harry, own a $5 billion real estate empire that includes 27 hotels - the Helmsley hotels in New York and the Harley chain based in Cleveland.

Helmsley was indicted with his wife in 1988 but was found mentally incompetent to stand trial. They still face prosecution on charges of evading state taxes; no trial date has been set.

Mrs. Helmsley was convicted of evading federal taxes from 1983 through 1985, most of it by fraudulently billing $3.1 million in expenses from the Helmsleys' Greenwich, Conn., mansion, Dunnellen Hall, to their business empire.

Among the expenses were more than $1 million for a pool enclosure with a marble dance floor; jade figures worth $500,000, and a $130,000 indoor-outdoor sound system.

Mrs. Helmsley's two co-defendants also will be sentenced Tuesday. Joseph Licari and Frank Turco, both former Helmsley executives, were convicted of helping in the tax fraud.