The Obama administration on Tuesday appealed a ruling that blocked federal funding of human embryonic stem cell research, asking the judge who issued the injunction to put it on hold pending the appeal.

The Justice Department asked Judge Royce Lamberth to lift the injunction he imposed last week after two doctors sued over the administration's policy, saying it violated U.S. law because it involved destroying embryos and that it also made it more difficult for them to win federal research grants.

Lamberth's injunction was harming current federally funded human embryonic stem cell research and could force a halt to all research that is subject to government funding, the Justice Department said in its request.

Numerous ongoing projects will likely not survive even a temporary gap in funds, jeopardizing both the potential benefit of the research and the hundreds of millions of dollars of taxpayer funds already invested in it, the filing said.

The two researchers had argued that the new policy broadening National Institutes of Health funding for human embryonic stem cell research made it harder for them to win grants for their adult stem cell research, an argument the Justice Department disputed.

The two doctor's remote economic self-interests do not outweigh the harm the injunction will cause NIH, the hundreds of affected human embryonic stem cell researchers, and the millions of individuals who hold out hope that human embryonic stem cell research will lead to the cure for, or treatment of, their currently incurable illnesses, the Justice Department said.

The administration pointed to 24 projects up for renewed federal funding between now and the end of September and said the benefits from the research could be lost.

The Justice Department asked Lamberth to rule by September 7 on the request to lift his injunction during the appeal.

President Barack Obama opened the door to broader federal funding of human embryonic stem cell research as one of his first acts after taking office in 2009, overturning his predecessor George W. Bush's limitations on the work.

The NIH issued guidelines for the research, which Dr. James Sherley, a biological engineer at Boston Biomedical Research Institute, and Theresa Deisher, of Washington-based AVM Biotechnology, then challenged.

Supporters of human embryonic stem cell research say it is vital to carry it out alongside other types of stem cell research to understand how to transform cells into desired tissue types and treat diseases ranging from juvenile diabetes to blindness.

Opponents say it is wrong to destroy human embryos, even days-old embryos to be discarded from fertility clinics.