ASHINGTON - Abortion opponents took aim yesterday at new federal guidelines on stem-cell research, accusing the Clinton administration of playing presidential politics with a science they call unethical and unlawful, and vowing to overturn the action in the courts or Congress.
The dilemma over research that has life-saving potential but that destroys human embryos has divided the major presidential candidates. Governor George W. Bush of Texas opposes the use of federal funds for it, while Vice President Al Gore supports it.
The issue could emerge in the campaign because it touches on abortion.
''It will be easy for this to become a political football,'' said Ronald Green, who directs the Ethics Institute at Dartmouth College. ''And because there is not a large constituency for patient-care groups, it is prone to get more emotional criticism than emotional support.''
The National Institutes of Health won praise yesterday from many scientists for riding out a heavy storm of criticism and publishing ethical and clinical guidelines that will allow medical researchers to obtain federal funds to study the fast-developing biology of embryonic stem cells.
The cells, which are culled from week-old human embryos and grow and differentiate into organs and tissue, show promise in treating many serious conditions, including diabetes, Alzheimer's, Parkinson's, and heart disease.
''I think that if the public will look at, first of all, the potentially staggering benefits of this research - everything from birth defects to Parkinson's, certain kinds of cancer, diabetes, spinal-cord injuries - it's a potential change for the future,'' President Clinton said yesterday. ''I think we cannot walk away from the potential to save lives and improve lives.''
The new policy was put in place despite a 1996 federal law, championed by abortion opponents in Congress, the National Right to Life Committee, and the National Conference of Catholic Bishops, that prohibits public funding of research in which human embryos are destroyed or discarded.
According to the NIH guidelines, the source of research stem cells must be frozen embryos left over from fertility treatments, and that, with the patient's consent, are to be discarded. The policy prohibits federal money from being spent on the process that separates the stem cells from the embryo, which results in the embryo's destruction.
Opponents said the guidelines were a transparent and politically motivated end run around the law.
''Embryonic stem-cell research is illegal, immoral, and unnecessary,'' Senator Sam Brownback, a Kansas Republican, said in a statement. He argues that researchers should concentrate on regenerating adult stem cells because it would make the abortion issue moot. ''It is never acceptable to deliberately kill one innocent human being in order to help another,'' he said.
Representative Jay Dickey, an Arkansas Republican who sponsored the 1996 funding ban, called the National Institutes of Health rules a ''boldfaced violation of the law.'' He said in an interview that he will seek either a court-ordered injunction or will try to withhold funds appropriated for the NIH if the agency makes a grant for stem-cell research.
Dickey also accused the Clinton administration of manipulating a federal agency to help Gore. ''The administration didn't have to bring this up right in the middle of the election,'' Dickey said. ''Their concern is not so much with science as it is with promoting the Clinton-Gore pro-abortion agenda.''
Gore, who supports abortion rights, is counting on raising the abortion issue often to help him win win over independent voters, particularly women. Aides to Gore and his running mate, Senator Joseph I. Lieberman of Connecticut, said both men support the NIH funding guidelines.
Bush, who opposes abortion except in cases of rape and incest, and to save the life of the mother, is wooing the same voters and is conducting a campaign in which the issue plays little or no role. ''Governor Bush opposes federal funding for stem-cell research when it involves destroying a living, human embryo,'' said Ray Sullivan, a spokesman for the campaign.
Bush supporters say that as president, he would issue an executive order overturning the policy. ''The question for the next president is whether he is going to enforce the plain letter of the law,'' said Douglas Johnson, legislative director of the National Right to Life Committee, which has endorsed Bush.
An overheated debate in Congress this fall may not benefit Bush, who asserts that he is a compassionate conservative. Dickey compared the NIH-approved research yesterday to ''the horrors committed by Nazi doctors,'' which ''taught us the lesson that `science' can sometimes be used to hide other agendas.''
But in a conference call arranged by the American Society for Cell Biology, Lyn Langbein of Olney, Md., described how stem-cell research may be the best therapeutic hope that children such as her 5-year-old daughter, Jamie, who suffers from juvenile diabetes, have of reaching age 20 as a healthy young woman.
''It scares me when I hear opponents to embryo research say, `Let's rely on adult stem cells,''' Langbein said. ''What if five years down the road we find they aren't about to do what we want them to do? Time is not on our side when it comes to juvenile diabetes.''
Scientists say it would be a mistake to pursue only one avenue of stem-cell research. Even in the best case, it will be at least three to five years before human clinical tests can begin. Researchers in cell biology say they are encouraged by experiments in animals, which have improved the mobility of those with spinal cord injuries.
The actor Christopher Reeve, who was paralyzed in a riding accident, has become a national spokesman for stem-cell research and raised money for the cause at the Democratic National Convention. Michael J. Fox, an actor with Parkinson's disease, now has a foundation and is also lobbying for a stem-cell breakthrough. He held a fund-raiser at the GOP convention.
''We believe the NIH guidelines will enable this critical research to advance without violating the moral and ethical sensibilities of the American people,'' said Paul Berg, a Stanford University biochemist who won a Nobel Prize for cancer research. ''It would be immoral not to proceed, in that it has the potential to save lives.''
