A Howard County judge yesterday gave Linda R. Tripp's attorneys until next week to decide whether they will call any witnesses to bolster their claim that Maryland prosecutors used improper evidence to charge her with illegally taping a phone call with Monica S. Lewinsky.

Tripp attorney Joseph Murtha told reporters that he is still contemplating whether to call his client to the stand, but he said, "My inclination is that it will not be necessary to call Mrs. Tripp."

Either way, Murtha said, Tripp's trial will be pushed back beyond its scheduled Jan. 18 date. The case could stretch far into next year as both sides may soon be fighting over Tripp's contention that her prosecution is politically motivated.

"This thing is going to last for a long time," Murtha said.

Howard Circuit Court Judge Diane O. Leasure said yesterday that she did not plan to decide until at least January what evidence, if any, the state may use to prosecute Tripp on charges that she illegally taped one of Lewinsky's calls and later disclosed the conversation to Newsweek magazine. Each of the two charges carries a maximum of five years in prison and $10,000 fine.

Leasure's ruling is considered crucial in whether prosecutors will have enough evidence to take Tripp to trial.

Murtha said he plans to file a motion arguing that State Prosecutor Stephen Montanarelli's case amounts to political revenge against Tripp, whose recordings formed the basis of President Clinton's impeachment.

Montanarelli, Maryland's state prosecutor for 15 years, is a governor-appointed Democrat. Maryland Attorney General J. Joseph Curran Jr., whose office is assisting in the prosecution, is also a Democrat. Leasure was appointed to the bench by Gov. Parris N. Glendening (D), although her neutrality has not been questioned by either side.

Montanarelli has steadfastly denied any political motivations.

"We've always maintained that we are an independent, nonpolitical office," Steven Halpert, a spokesman for Montanarelli, said yesterday.

Murtha said he may file at least three other challenges to the prosecution's case, each involving complex constitutional issues.

Tripp's attorneys are seeking to have evidence excluded from the trial--and even to have the whole case thrown out--by arguing that Maryland prosecutors based the charges against Tripp on "tainted" evidence.

The prosecution, Tripp's attorneys say, has evidence that stemmed from Tripp's cooperation with former independent counsel Kenneth W. Starr's office after she was granted federal immunity. Evidence gathered from a person who has been granted immunity cannot be used against them in court.

Prosecutors argue that they found witnesses based solely on their own investigation. Prosecutors also said their witnesses told the Howard grand jury that indicted Tripp only what they recalled about her recordings from their own memories and not from the media reports or the Starr report to Congress.

Tripp waived her right to be present at this week's five-day hearing, missing Lewinsky's first public court appearance Thursday. The former White House intern testified that she never gave Tripp permission to tape their phone calls. Lewinsky also said she was "frightened" to find one of their conversations concerning her affair with the president published in Newsweek magazine.

Leasure said she will determine whether any evidence against Tripp is "tainted" and, if so, how much of the state's evidence should be excluded from trial. The judge said she also may consider, if she finds any improper evidence, whether the entire case should be thrown out.

But Maryland prosecutors, in wrapping up the defense of their evidence yesterday, said they did not rely on Starr's office to build their case.

Thomas McDonough, an assistant state prosecutor, testified yesterday that his office believed almost immediately upon reading the Feb. 2, 1998, Newsweek article, which included a transcript of the recording in question, that they had a solid wiretapping case against Lewinsky's former friend.

"It was absolutely clear that every element of a wiretapping case in Maryland . . . was publicized very early on," he said.

McDonough said prosecutors also discovered on their own two lawyers who said they discussed with Tripp during Paula Jones's sexual harassment lawsuit against Clinton that the phone call recordings were illegal before she made the tape in question.

Under cross-examination, Murtha pressed McDonough about a copy of the Starr report to Congress kept in the state prosecutor's office. The report contains information that Tripp gave prosecutors while immunized.

McDonough said that he did not read the Starr report and that prosecutors did not use it in compiling their case against Tripp.

CAPTION: Maryland State Prosecutor Stephen Montanarelli arrives at court for a pretrial hearing in the Linda R. Tripp case.

CAPTION: Joseph Murtha, right, defense attorney for Tripp, is accompanied by a Howard County sheriff's officer.