President Clinton is strongly considering making a request for government reimbursement of several million dollars in legal expenses associated with the Whitewater and Monica S. Lewinsky investigations, a move the independent counsel's office is already preparing to challenge, knowledgeable legal sources said yesterday.

If successful, Clinton and first lady Hillary Rodham Clinton could eliminate most or all of their $5 million in unpaid legal bills, the balance of a sum that once exceeded $10 million. The move also would add to the $47 million the public has paid thus far for the independent counsel's five-year investigation of the Clintons. That includes Kenneth W. Starr's efforts that led to the president's impeachment a year ago Sunday.

Anticipating the Clintons' application for reimbursement, the independent counsel's office has been examining court rulings that could help it block or limit the effort. While both Presidents Ronald Reagan and George Bush were reimbursed for legal fees they incurred in the Iran-contra investigation, other targets of independent counsel investigations have been unable to meet the legal requirements for reimbursement, including showing that they would not have been pursued by a regular prosecutor.

"There will be a challenge" to the Clintons' reimbursement request, said a lawyer in the independent counsel's office, now headed by Starr's successor, Robert Ray. A panel of federal judges rules on fee reimbursement requests.

Clinton's lawyers, led by David E. Kendall, declined to comment on the matter. Washington lawyers familiar with the situation, however, said they fully expect the team to apply for several million dollars in fee reimbursement once the independent counsel's office issues its final report on the lengthy probe into the president and the first lady.

It is unclear when that will happen. "No final reports are imminent," deputy independent counsel Edward J. Page said yesterday. "They are works in progress."

The act authorizing the appointment of independent counsels included a reimbursement provision aimed at protecting innocent parties ensnared in investigations that force them to run up large legal expenses. Thus far, 58 people--many of them White House staffers--have requested legal fee reimbursements stemming from Starr's investigation. Ten have received payments, which totaled $27,356, the Justice Department said yesterday. While the law expired in the summer, its provisions still apply to the Clinton case.

By law, Page said, the subjects or targets of investigations may recoup reasonable attorney's fees if they are not indicted and if they would not have needed a lawyer "but for the independent counsel statute." While some might argue that impeachment is tantamount to indictment, knowledgeable lawyers say Ray's office is more likely to base its challenge of Clinton's request on the so-called "but for" clause.

The clause requires applicants for reimbursement to show that they probably would have escaped investigation by regular prosecutors. That's what former attorney general Edwin Meese successfully argued in 1990, when he was reimbursed for $460,509 in legal expenses he incurred in the Wedtech Corp. probe during the Reagan administration.

A U.S. appeals court cited several factors--including that Meese had asked to be investigated--in concluding that he was subjected to a "more vigorous application of criminal law than was applied to other citizens."

But the same court in 1991 rejected a reimbursement request from Lyn Nofziger, a White House adviser early in Reagan's term. Nofziger's conviction on illegal lobbying charges stemming from the Wedtech case had been overturned, and his indictment had been ruled invalid. But the court barred the reimbursement of his lawyers' fees, arguing that a federal prosecutor would have targeted him had there been no independent counsel.

Lawyers say such arguments will determine how much money, if any, the Clintons recoup from the government. Clinton's strongest argument, some say, could involve his and his wife's roles in the complex Whitewater matter, in which they often were little more than witnesses. More contentious, they say, will be arguments over the president's alleged perjury in the Paula Jones sexual harassment case.

Some legal experts say no reasonable prosecutor would have pursued perjury charges in such a case if Clinton had been an ordinary citizen, giving weight to a "but for" claim for fee reimbursement. Others say he shouldn't qualify for reimbursement because a regular federal prosecutor would have pursued Clinton in such a case.

Rep. Robert L. Barr Jr. (R-Ga.), a House manager in the impeachment trial, said he would oppose any effort by Clinton to recoup legal expenses.

"It doesn't surprise me at all, but I do intend to look into this and do everything I can to ensure the president doesn't get away with this," Barr said. A reimbursement "would be very improper, but the chutzpah of this administration knows no bounds."

Barr questioned the possible reimbursement request on several legal grounds, arguing that the reimbursement provision in the independent counsel statute did not intend to cover impeachment.

Rep. James P. Moran Jr. (D-Va.) said he is sure the question of Clinton's legal fees "will become a very controversial issue. I could list off a hundred Republicans who would love to debate this issue on the floor of the House."

But Democrats may find an ally in House Judiciary Committee Chairman Henry J. Hyde (R-Ill.), who sought Clinton's removal from office but also supports the reimbursement of legal fees to defendants who have been wrongfully prosecuted.

"The president is neither above the law nor below it," said Hyde spokesman Sam Stratman. "This is a remedy open to the president if he is indeed not indicted."

Clinton supporters have contributed about $5 million to a legal defense fund that helps the first family pay lawyers who have defended them in several matters, including the Whitewater case, the firing of employees in the White House travel office, the Jones case and allegations that Clinton lied under oath about his affair with Lewinsky, a former White House intern. At his impeachment trial, which ended in a Senate acquittal, Clinton was represented by both government and private lawyers.

Peter J. Lavallee, administrator of the Clinton legal defense trust, said refunds will be given--starting with the most recent donors--if a government reimbursement exceeds the Clintons' outstanding legal fees. Sources familiar with the fees said about two-thirds of the $10 million total stems from independent counsel investigations, and thus could be covered by a request for reimbursement. The remaining costs stem largely from Jones's civil lawsuit, which would not be subject to reimbursement.

Staff writer Juliet Eilperin contributed to this report.